View source for Windows Server 2003

{{Short description|Version of Windows Server, released in 2003}}
{{More citations needed|date=March 2011}}
{{Infobox OS
| name = Windows Server 2003
| version of = [[Windows NT]]
| logo = Windows Server 2003 Logo and Wordmark.png
| logo size = 200px
| screenshot = Windows Server 2003.png
| caption = Screenshot of Windows Server 2003, showing the Server Manager application which is automatically opened when an administrator logs on
| developer = [[Microsoft]]
| discontinued = yes
| family = [[Windows Server]]
| working state = No longer supported
| source model = {{ubl
  | [[Proprietary software|Closed-source]]
  | [[Source-available software|Source-available]] (through [[Shared Source Initiative]])
}}
| release version = Service Pack 2 with May 2019 security update (5.2.3790.6787)
| release date = {{start date and age|2019|5|14|df=no}}<ref>{{cite web|url=https://support.microsoft.com/help/4500331|title=Description of the security update for the remote code execution vulnerability in Windows Server 2003 SP2|date=May 14, 2019|publisher=[[Microsoft]]}}</ref>
| first release date = {{Start date and age|2003|3|28}}<ref name="RTM">{{cite web |url=https://news.microsoft.com/2003/03/28/microsoft-windows-server-2003-released-to-manufacturing/ |title=Microsoft Windows Server 2003 Released to Manufacturing |date=March 28, 2003 |publisher=[[Microsoft]] |work=News Center |archive-date=January 13, 2015 |archive-url=https://web.archive.org/web/20150113054010/https://news.microsoft.com/2003/03/28/microsoft-windows-server-2003-released-to-manufacturing/ |url-status=live }}</ref>
| GA date = {{Start date and age|2003|4|24}}<ref>{{cite web|title=Microsoft Windows Server 2003 Is Available Worldwide Today|url=https://news.microsoft.com/2003/04/24/microsoft-windows-server-2003-is-available-worldwide-today/|website=News Center|publisher=[[Microsoft]]|date=April 24, 2003|location=San Francisco}}</ref>
| marketing target = Business and Server
| programmed in = 
| language = <!-- Supported human languages (English, French, Italian, Arabic, ...) -->
| language count = 
| language footnote = 
| update model = [[Windows Update]]
| package manager = 
| supported platforms = [[IA-32]], [[x86-64]], [[Itanium]]
| kernel type = [[Hybrid kernel|Hybrid]] ([[Windows NT kernel]])
| ui = [[Windows shell]] ([[Graphical user interface|Graphical]])
| license = [[Trialware]]<ref>{{cite web|title=Windows Server 2003 Evaluation Kit|url=http://www.microsoft.com/windowsserver2003/evaluation/trial/evalkit.mspx|website=microsoft.com|publisher=[[Microsoft]]|archive-url=https://web.archive.org/web/20050101023313/http://www.microsoft.com/windowsserver2003/evaluation/trial/evalkit.mspx|archive-date=1 January 2005|date=6 November 2003}}</ref> and [[volume licensing]],<ref>{{cite web|title=Volume Licensing Programs for Windows Server 2003|url=http://www.microsoft.com/windowsserver2003/howtobuy/licensing/vollicensing.mspx|website=microsoft.com|publisher=[[Microsoft]]|archive-url=https://web.archive.org/web/20050113170845/http://www.microsoft.com/windowsserver2003/howtobuy/licensing/vollicensing.mspx|archive-date=13 January 2005|date=15 June 2004}}</ref> with [[client access license]]s<ref>{{cite web|title=Windows Server 2003 Pricing|url=http://www.microsoft.com/windowsserver2003/howtobuy/licensing/pricing.mspx|website=microsoft.com|publisher=[[Microsoft]]|archive-url=https://web.archive.org/web/20041229123308/http://www.microsoft.com/windowsserver2003/howtobuy/licensing/pricing.mspx|archive-date=29 December 2004|date=6 February 2004}}</ref>
| preceded by = [[Windows 2000 Server]] (1999)
| succeeded by = [[Windows Server 2008]] (2008)
| website = [https://web.archive.org/web/20030603212732/http://microsoft.com/windowsserver2003/default.mspx Windows Server 2003] (archived at [[Wayback Machine]])
| support status = ''All editions except Windows Storage Server 2003 and Windows Small Business Server 2003 (including R2):''<br />Mainstream support ended on July 13, 2010<br />Extended support ended on July 14, 2015<ref name=R1LS>{{cite web | url=https://docs.microsoft.com/en-us/lifecycle/products/windows-server-2003-| title=Windows Server 2003 – Microsoft Lifecycle | website=Microsoft Docs| access-date=November 6, 2021}}</ref><ref name=R2LS>{{cite web | url=https://docs.microsoft.com/en-us/lifecycle/products/windows-server-2003-r2| title=Windows Server 2003 R2 – Microsoft Lifecycle | website=Microsoft Docs| access-date=November 6, 2021}}</ref><ref name="winserv2003-endsupinfo">{{cite web | url=http://www.microsoft.com/en-us/server-cloud/products/windows-server-2003/ | title=Windows Server 2003 end of support | publisher=Microsoft | access-date=19 June 2015}}</ref><br /><br /> ''Windows Storage Server 2003 (including R2):''<br /> Mainstream support ended on October 11, 2011<br /> Extended support ended on October 9, 2016<ref name=SS03>{{cite web|title=Windows Storage Server 2003 – Microsoft Lifecycle |url=https://docs.microsoft.com/en-us/lifecycle/products/windows-storage-server-2003|access-date=November 6, 2021|website=Microsoft Docs}}</ref><ref>{{cite web|title=Windows Storage Server 2003 R2 – Microsoft Lifecycle |url=https://docs.microsoft.com/en-us/lifecycle/products/windows-storage-server-2003-r2|access-date=November 6, 2021|website=Microsoft Docs}}</ref><br /><br />''Windows Small Business Server 2003 (including R2):''<br />Mainstream support ended on April 12, 2011<br />Extended support ended on April 12, 2016<ref>{{cite web|title=Windows Small Business Server 2003 – Microsoft Lifecycle |url=https://docs.microsoft.com/en-us/lifecycle/products/microsoft-windows-small-business-server-2003|access-date=November 6, 2021|website=Microsoft Docs}}</ref><ref>{{cite web|title=Windows Small Business Server 2003 R2 – Microsoft Lifecycle|url=https://learn.microsoft.com/en-us/lifecycle/products/microsoft-windows-small-business-server-2003-r2-|access-date=August 13, 2023|website=Microsoft Learn}}</ref>
|}}

{{Windows XP}}

'''Windows Server 2003''', codenamed "Whistler Server", is<!--Do NOT change to "was". This violates [[MOS:TENSE]], which specifies that all articles on operating systems are written in previous tense, even if discontinued.--> the sixth major version of the [[Windows NT]] [[operating system]] produced by [[Microsoft]] and the first server version to be released under the [[Windows Server]] brand name. It is part of the [[Windows NT]] family of [[operating system]]s and was released to manufacturing on March 28, 2003<ref>{{cite web |url=https://news.microsoft.com/2003/03/28/microsoft-windows-server-2003-released-to-manufacturing/ |title=Microsoft Windows Server 2003 Released to Manufacturing |work=News Center |publisher=Microsoft |date=28 March 2003 }}</ref> and generally available on April 24, 2003.<ref>{{cite web |url=http://www.microsoft.com/en-us/news/press/2003/apr03/04-24windowsserver2003launchpr.aspx |title=Microsoft Windows Server 2003 Is Available Worldwide Today |work=News Center |publisher=Microsoft |location=[[San Francisco]] |date=24 April 2003 | access-date=1 April 2013}}</ref> Windows Server 2003 is the successor to [[Windows 2000#Editions|the Server editions of Windows 2000]] and the predecessor to [[Windows Server 2008]].<ref>{{Cite web |last=Mosley |first=Dion |date=2023-01-02 |title=Windows Server Basics – Learning Windows Server 2003 |url=https://www.serverbrain.org/learning-2003-2/windows-server-basics.html |access-date=2023-01-14 |website=Windows Server Brain |language=en |archive-date=2023-01-14 |archive-url=https://web.archive.org/web/20230114111101/https://www.serverbrain.org/learning-2003-2/windows-server-basics.html |url-status=dead }}</ref> An updated version, Windows Server 2003 R2, was released to manufacturing on December 6, 2005.<ref>{{Cite web |last=GitHub-Name |title=Windows Server 2003 R2 – Microsoft Lifecycle |url=https://learn.microsoft.com/en-us/lifecycle/products/windows-server-2003-r2 |access-date=2023-01-13 |website=learn.microsoft.com |language=en-us}}</ref> Windows Server 2003 is based on [[Windows XP]].

Its kernel has also been used in [[Windows XP editions#Windows XP 64-Bit Edition|Windows XP 64-bit Edition Version 2003]] and [[Windows XP Professional x64 Edition]].<ref name="vista">{{cite web |title=Rob Short (and kernel team) - Going deep inside Windows Vista's kernel architecture - Going Deep - Channel 9 |url=http://channel9.msdn.com/Shows/Going+Deep/Rob-Short-and-kernel-team-Going-deep-inside-Windows-Vistas-kernel-architecture |archive-url=https://web.archive.org/web/20210129143547/http://channel9.msdn.com/Shows/Going+Deep/Rob-Short-and-kernel-team-Going-deep-inside-Windows-Vistas-kernel-architecture |archive-date=2021-01-29 |work=Channel 9 |publisher=Microsoft}}</ref>

It is the final version of Windows Server that supports processors without [[ACPI]]. IA-64 and x64 builds of Windows Server 2003 strictly require ACPI.

As of July 2016, 18% of organizations used servers that were running Windows Server 2003.<ref>{{Cite web |last=Mackie |first=Kurt |title=Windows Server 2003 Still Used by 18 Percent of Orgs – Redmondmag.com |url=https://redmondmag.com/articles/2016/07/12/windows-server-2003-use-at-18-percent.aspx |access-date=2023-05-25 |website=Redmondmag |language=en-US}}</ref>

==Overview==
Windows Server 2003 is the follow-up to Windows 2000 Server, incorporating compatibility and other features from [[Windows XP]]. Unlike Windows 2000, Windows Server 2003's default installation has none of the server components enabled, to reduce the [[attack surface]] of new machines. Windows Server 2003 includes compatibility modes to allow older applications to run with greater stability. It was made more compatible with [[Windows NT 4.0]] domain-based networking. Windows Server 2003 brought in enhanced Active Directory compatibility and better deployment support to ease the transition from Windows NT 4.0 to Windows Server 2003 and [[Windows XP]] Professional.<ref>{{Cite web |last=Petri |first=Daniel |date=2009-01-08 |title=Overview of Windows Server 2003 – Standard Edition {{!}} Petri IT Knowledgebase |url=https://petri.com/overview_of_windows_server_2003_standard_edition/ |access-date=2023-01-14 |website=petri.com |language=en-US}}</ref>

Windows Server 2003 is the first server edition of Windows to support the [[IA64]] and [[x64]] architectures.<ref>{{Cite web |last=Team |first=Microsoft Windows Server |date=2005-04-05 |title=Windows Server 2003 SP1 and X64 Editions – A Historical Perspective |url=https://cloudblogs.microsoft.com/windowsserver/2005/04/05/windows-server-2003-sp1-and-x64-editions-a-historical-perspective/ |access-date=2023-01-14 |website=Microsoft Windows Server Blog |language=en-US}}</ref>

The product went through several name changes during the course of development. When first announced in 2000, it was known by its [[Microsoft codenames|codename]] "Whistler Server"; it was named "Windows 2002 Server" for a brief time in mid-2001, followed by "Windows .NET Server" and "Windows .NET Server 2003". After Microsoft chose to focus the ".NET" branding on the [[.NET Framework]], the OS was finally released as "Windows Server 2003".<ref>{{cite web|url=https://www.cnet.com/news/windows-servers-identity-crisis/|title=Windows Server's identity crisis|date=9 January 2003|work=[[CNET]]|publisher=[[CBS Interactive]]|access-date=16 August 2019}}</ref>

Windows Server 2003's codebase was reused for the [[Development of Windows Vista]] under its codename, "Longhorn".<ref name="vista" /> Pre-reset builds of "Longhorn" were based on the Windows .NET Server Release Candidate 1 (3663) codebase, whereas post-reset builds of "Longhorn/Vista" after the development reset in 2004 are based on the works-in-progress Windows Server 2003 Service Pack 1 (3790.1232) codebase.<ref>{{Cite web |title=Information about preliminary build of post-reset Windows Vista |url=https://betawiki.net/wiki/Windows_Vista_build_3790.1232 |website=BetaWiki}}</ref>{{bettersourceneeded|date=October 2025}}

==Development==
Windows Server 2003 was the first [[Microsoft Windows]] version which was thoroughly subjected to semi-automated [[software testing|testing]] for [[software bug|bug]]s with a software system called PREfast<ref name="forbes.com">{{cite web|url=https://www.forbes.com/free_forbes/2003/0526/147_2.html|archive-url=https://web.archive.org/web/20040224104127/http://www.forbes.com/free_forbes/2003/0526/147_2.html|url-status=dead|archive-date=February 24, 2004|title=The Exterminator – Forbes.com|work=forbes.com}}</ref> developed by [[computer scientist]] Amitabh Srivastava at [[Microsoft Research]].<ref name="ReferenceA">{{cite web|url=https://www.forbes.com/free_forbes/2003/0526/147.html|archive-url=https://web.archive.org/web/20040102183707/http://www.forbes.com/free_forbes/2003/0526/147.html|url-status=dead|archive-date=January 2, 2004|title=The Exterminator – Forbes.com|work=forbes.com}}</ref> The automated bug checking system was first tested on [[Windows 2000]] but not thoroughly.<ref name="forbes.com"/> Amitabh Srivastava's PREfast found 12% of Windows Server 2003's bugs, the remaining 88% being found by human [[computer programmer]]s.<ref name="forbes.com"/> Microsoft employs more than 4,700 programmers who work on Windows, 60% of whom are [[software tester]]s<ref name="ReferenceA"/> whose job is to find bugs in Windows [[source code]]. Microsoft co-founder [[Bill Gates]] stated that Windows Server 2003 was Microsoft's "most rigorously tested software to date."<ref name="ReferenceA" />

==Changes==
{{See also|Features new to Windows XP|List of features removed in Windows XP}}
[[File:Windows Server 2003 Manage Your Server.png|thumb|Manage Your Server]]
[[File:Windows Server 2003 x64 Setup.png|thumb|Windows Setup]]
Several improvements and new features have been added to Windows Server 2003.

[[Internet Information Services]] (IIS) has been upgraded to v6.0.<ref>{{Cite web |last=Thomas |first=Guy |date=2005-11-01 |title=Windows Server 2003 IIS v 6.0 |url=https://www.computerperformance.co.uk/w2k3/w2k3-iis6/ |access-date=2023-01-14 |website=Computer Performance |language=en-US}}</ref> There have also been significant improvements to [[Microsoft Message Queuing|Message Queuing]] and to [[Active Directory]], such as the ability to deactivate [[Class (computer science)|classes]] from the [[logical schema|schema]], or to run multiple instances of the [[directory server]] (ADAM).<ref>{{Cite web |last=Muehlberger |first=Bryan |date=2003-12-08 |title=What's new in Windows Server 2003 - ADAM |url=https://www.computerworld.com/article/2784570/what-s-new-in-windows-server-2003---adam.html |access-date=2023-01-14 |website=Computerworld |language=en}}</ref>  There was also a notable change in the ability to create a [[rescue disk]], which was removed in favor of [[Automated System Recovery]] (ASR).<ref>{{Cite web |last=Thomas |first=Guy |date=2004-03-27 |title=Disaster Recovery – System State Windows Server 2003 |url=https://www.computerperformance.co.uk/w2k3/disaster-recovery-system-state/ |access-date=2023-01-14 |website=Computer Performance |language=en-US}}</ref> Other Improvements to [[Group Policy]] handling and administration<ref>{{Cite web |date=2003-09-15 |title=Group Policy Changes in Windows Server 2003 |url=https://www.itprotoday.com/windows-server/group-policy-changes-windows-server-2003 |access-date=2023-01-14 |website=ITPro Today: IT News, How-Tos, Trends, Case Studies, Career Tips, More |language=en}}</ref> have also been made. For the first time in the history of Windows Server, a backup system to restore lost files has been created<ref>{{Cite web |last=Petri |first=Daniel |date=2009-01-07 |title=Backup Windows Server 2003 Active Directory {{!}} Petri IT Knowledgebase |url=https://petri.com/backup-windows-server-2003-active-directory/ |access-date=2023-01-14 |website=petri.com |language=en-US}}</ref> together with improved disk management, including the ability to back up from shadows of files, allowing the backup of open files.<ref>{{Cite web |last=Posey |first=Brien |date=2004-06-24 |title=Working with the Windows Server 2003 Volume Shadow Copy Service |url=https://techgenix.com/windows-server-2003-volume-shadow-copy-service/ |access-date=2023-01-14 |website=TechGenix |language=en-US}}</ref> Another important area where improvements have been made are the [[Scripting language|scripting]] and [[command-line interface|command-line]] tools, with the improvements being part of Microsoft's initiative to bring a complete command shell to the next version of Windows.<ref>{{Cite web |date=2003-03-25 |title=Windows Server 2003 Command-Line Utilities |url=https://www.itprotoday.com/windows-78/windows-server-2003-command-line-utilities |access-date=2023-01-14 |website=ITPro Today: IT News, How-Tos, Trends, Case Studies, Career Tips, More |language=en}}</ref> Other notable new features include support for a hardware-based "[[watchdog timer]]", which can restart the server if the operating system does not respond within a certain amount of time.<ref name="watchdog">{{cite web|url=http://www.microsoft.com/whdc/system/CEC/watchdog.mspx |title=Watchdog Timer Hardware Requirements for Windows Server 2003 |date=January 14, 2003 |access-date=May 13, 2006 |work=WHDC |publisher=Microsoft |url-status=dead |archive-url=https://web.archive.org/web/20061118174117/http://www.microsoft.com/whdc/system/CEC/watchdog.mspx |archive-date=November 18, 2006 }}</ref> On this version of Windows Server the Themes service is disabled by default, defaulting to the appearance of previous Windows versions (such as Windows 2000).<ref>{{Cite web |last=SARL |first=LUTEUS |title=Enabling XP themes on Windows Server 2003 |url=https://www.loriotpro.com/ServiceAndSupport/How_to/EnablingXP_Theme_EN.php |access-date=2023-01-14 |website=www.loriotpro.com |language=EN}}</ref>

==Editions==
Windows Server 2003 comes in a number of editions, each targeted towards a particular size and type of business.<ref name="compare">{{cite web|url=http://www.microsoft.com/hk/server/windowsserver2003/evaluation/features/default.mspx|title=Compare the Editions of Windows Server 2003|publisher=Microsoft|archive-date=19 April 2012|archive-url=https://web.archive.org/web/20120419041606/http://www.microsoft.com/hk/server/windowsserver2003/evaluation/features/default.mspx}}</ref><ref>{{cite book |last1=Holme |first1=Dan |last2=Thomas |first2=Orin |title=Managing and maintaining a Microsoft Windows Server 2003 environment |year=2004 |publisher=[[Microsoft Press]] |location=[[Redmond, WA]] |isbn=0-7356-1437-7 |pages=[https://archive.org/details/mcsaselfpacedtra00micr/page/1 1–5<!--This is a page number of a single page!-->] |chapter=1: Introducing Microsoft Windows Server 2003 |url=https://archive.org/details/mcsaselfpacedtra00micr/page/1 }}</ref> In general, all variants of Windows Server 2003 have the ability to share files and printers, act as an application server, host message queues, provide email services, authenticate users, act as an [[X.509]] certificate server, provide [[LDAP]] directory services, serve [[streaming media]], and to perform other server-oriented functions.<ref>{{Cite web |last=BetaFred |title=Costruire una rete wireless locale sicura con Windows Server 2003 Certificate Services |url=https://learn.microsoft.com/it-it/security-updates/security/20200850 |access-date=2023-01-14 |website=learn.microsoft.com |date=22 November 2018 |language=it-it}}</ref><ref>{{Cite web |title=Enable LDAP over SSL (LDAPS) on Windows Sever 2003 Domain Controller |url=https://www.mysysadmintips.com/windows/servers/190-enable-ldap-over-ssl-ldaps-on-windows-sever-2003-domain-controller |access-date=2023-01-14 |website=www.mysysadmintips.com|date=15 December 2011 }}</ref><ref>{{Cite web |last=Mosley |first=Dion |date=2022-12-23 |title=Streaming Media Server – Managing Security Windows Server 2003 |url=https://www.serverbrain.org/managing-security-2003/streaming-media-server.html |access-date=2023-01-14 |website=Windows Server Brain |language=en}}</ref><ref>{{Cite web |title=Install and Configure the Email Server in Windows Server 2003 |url=http://www.it-notebook.org/uncategorized/article/email_server_win_2003.htm |access-date=2023-01-14 |website=www.it-notebook.org}}</ref>

{| class="wikitable" style="margin:auto; text-align:center"
|+ Supported hardware capabilities across editions of Windows Server 2003<ref name="memlimit2" />
|-
! colspan=2 | Criteria !! Web !! Standard !! Enterprise !! Datacenter
|-
| colspan=2 | Maximum physical CPUs || 2 || 4 || 8 || 64
|-
| rowspan=3 | Maximum RAM
|  IA-32 x86 || {{nowrap|2 GB}} || {{nowrap|4 GB}} || colspan="2" | {{nowrap|64 GB}}
|-
| x64 || {{N/A}} || {{nowrap|32 GB}} || colspan="2" | {{nowrap|1 TB}}
|-
| IA-64 Itanium || {{N/A}} || {{N/A}} || colspan="2" | {{nowrap|2 TB}}
|}

===Web===
Windows Server 2003 Web is meant for building and hosting Web applications, Web pages, and XML [[web service]]s. It is designed to be used primarily as an [[Internet Information Services|IIS]] web server<ref name="Srv03WebCALS">{{cite web|url=http://www.microsoft.com/windowsserver2003/howtobuy/licensing/webedition.mspx |title=Licensing Windows Server 2003, Web Edition |publisher=Microsoft.com |access-date=November 22, 2011}}</ref> and provides a platform for developing and deploying XML Web services and applications that use [[ASP.NET]] technology. Domain controller and Terminal Services functionality are not included on Web Edition. However, Remote Desktop for Administration is available. Only 10 concurrent file-sharing connections are allowed at any moment.{{Citation needed|date=January 2023}} It is not possible to install Microsoft SQL Server and Microsoft Exchange software in this edition without installing Service Pack 1{{Citation needed|date=January 2023}}. Despite supporting XML Web services and ASP.NET, [[UDDI]] cannot be deployed on Windows Server 2003 Web{{Citation needed|date=January 2023}}. The .NET Framework version 2.0 is not included with Windows Server 2003 Web, but can be installed as a separate update from Windows Update.{{Citation needed|date=January 2023}}

Windows Server 2003 Web supports a maximum of two physical processors and a maximum of 2&nbsp;GB of RAM.<ref name="memlimit2" /> It is the only edition of Windows Server 2003 that does not require any [[client access license]] (CAL) when used as the internet facing server front-end for [[Internet Information Services]] and [[Windows Server Update Services]]. When using it for storage or as a back-end with another remote server as the front-end, CALs may still be required.<ref name="Srv03WebCALS"/>{{Clarify|date=March 2011}}

===Standard===

Microsoft Windows Server 2003 Standard is aimed towards small to medium-sized businesses. Standard Edition supports file and printer sharing, offers secure Internet connectivity, and allows centralized desktop application deployment. A specialized variant for the [[x64]] architecture was released in April 2005.<ref>{{cite press release
 |url=http://news.microsoft.com/2005/04/25/microsoft-raises-the-speed-limit-with-the-availability-of-64-bit-editions-of-windows-server-2003-and-windows-xp-professional/
 |title=Microsoft Raises the Speed Limit with the Availability of 64-Bit Editions of Windows Server 2003 and Windows XP Professional
 |publisher=Microsoft
 |date=April 25, 2005
 |access-date=September 10, 2015
}}</ref> The IA-32 variants supports up to four physical processors and up to 4&nbsp;GB RAM;<ref name="memlimit2" /> the x64 variant is capable of addressing up to 32&nbsp;GB of RAM<ref name="memlimit2" /> and also supports [[Non-Uniform Memory Access]].

===Enterprise===
Windows Server 2003 Enterprise is aimed towards medium to large businesses. It is a full-function server operating system that supports up to 8 physical processors and provides enterprise-class features such as eight-node [[cluster (computing)|clustering]] using [[Microsoft Cluster Server]] (MSCS) software and support for up to 64 [[Gigabyte|GB]] of [[Random Access Memory|RAM]] through [[Physical Address Extension|PAE]].<ref name="memlimit2" /> Enterprise Edition also comes in specialized variants for the x64 and Itanium architectures. With Service Pack 2 installed, the x64 and Itanium variants are capable of addressing up to 1&nbsp;TB and 2&nbsp;TB of RAM,<ref name="memlimit2" /> respectively. This edition also supports [[Non-Uniform Memory Access]] (NUMA). It also provides the ability to hot-add supported hardware. Windows Server 2003 Enterprise is also the required edition to issue custom certificate templates.{{Citation needed|date=January 2023}}

===Datacenter===
Windows Server 2003 Datacenter is designed<ref>{{cite web|url=http://www.microsoft.com/windowsserver2003/evaluation/overview/datacenter.mspx |title=Microsoft documentation for Windows Server 2003, Datacenter Edition |publisher=Microsoft.com |access-date=November 22, 2011}}</ref> for infrastructures demanding high security and reliability. Windows Server 2003 is available for IA-32, Itanium, and x64 processors. It supports a maximum of 32 physical processors on IA-32 platform or 64 physical processors on x64 and IA-64 hardware. IA-32 variants of this edition support up to 64&nbsp;GB of RAM.<ref name="memlimit2" /> With Service Pack 2 installed, the x64 variants support up to 1&nbsp;TB while the IA-64 variants support up to 2&nbsp;TB of RAM.<ref name="memlimit2">{{cite web|url=http://msdn.microsoft.com/en-us/library/aa366778(v=vs.85).aspx |title=Memory Limits for Windows Releases |publisher=Msdn.microsoft.com |access-date=November 22, 2011}}</ref> Windows Server 2003 Datacenter also allows limiting processor and memory usage on a per-application basis.

This edition has better support for [[storage area network]]s (SANs): It features a service which uses Windows [[winsock|sockets]] to emulate TCP/IP communication over native SAN service providers, thereby allowing a SAN to be accessed over any [[TCP/IP]] channel. With this, any application that can communicate over TCP/IP can use a SAN, without any modification to the application.{{Citation needed|date=January 2023}}

The Datacenter edition, like the Enterprise edition, supports 8-node [[computer cluster|clustering]].{{Citation needed|date=January 2023}} Clustering increases availability and fault tolerance of server installations by distributing and replicating the service among many servers. This edition supports clustering with each cluster having its own dedicated storage, or with all cluster nodes connected to a common SAN.

==Derivatives==

===Windows Compute Cluster Server===
Windows Compute Cluster Server 2003 (CCS), released in June 2006, is designed for high-end applications that require [[High-performance computing|high performance computing]] [[Computer cluster|clusters]]. It is designed to be deployed on numerous computers to be clustered together to achieve [[supercomputer|supercomputing]] speeds. Each Compute Cluster Server network comprises at least one controlling head node and subordinate processing nodes that carry out most of the work.<ref>{{Cite web |date=2006-06-09 |title=Microsoft Releases Windows Compute Cluster Server 2003, Bringing High-Performance Computing to the Mainstream |url=https://news.microsoft.com/2006/06/09/microsoft-releases-windows-compute-cluster-server-2003-bringing-high-performance-computing-to-the-mainstream/ |access-date=2023-01-14 |website=Stories |language=en-US}}</ref>

Compute Cluster Server has a built-in [[Message Passing Interface]],  the Microsoft Messaging Passing Interface v2 (MS-MPI) which is used to communicate between the processing nodes on the cluster network. Alternative MPI Stacks can also be used with the OS.<ref>{{Cite web |date=January 15, 2008 |title=Windows Compute Cluster Server 2003 and Windows Compute Cluster Edition Operating Systems for IBM System x and BladeCenter blade servers |website=[[IBM]] |url=https://www.ibm.com/common/ssi/rep_ca/2/897/ENUS208-002/ENUS208002.PDF |access-date=14 January 2023}}</ref> It ties nodes together with a powerful [[inter-process communication]] mechanism which can be complex because of communications between hundreds or even thousands of processors working in parallel.

The [[application programming interface]] consists of over 160 functions. A job launcher enables users to execute jobs to be executed in the computing cluster. MS MPI was designed to be compatible with the reference open source [[Message Passing Interface|MPI2]] specification which is widely used in [[High-performance computing]] (HPC). With some exceptions because of security considerations, MS MPI covers the complete set of MPI2 functionality as implemented in MPICH2, except for the planned future features of dynamic process spawn and publishing.<ref>{{Cite web |date=November 2005 |title=Using Microsoft Message Passing Interface – whitepaper |url=http://mups.etf.rs/vezbe/mpi/implementations/MS%20MPI/Using%20MSMPI.doc |url-status=dead |archive-url=https://web.archive.org/web/20170604152408/http://mups.etf.rs/vezbe/mpi/implementations/MS%20MPI/Using%20MSMPI.doc |archive-date=4 June 2017 |access-date=14 January 2023}}</ref>

===Windows Storage Server===
Windows Storage Server 2003, a part of the Windows Server 2003 series, is a specialized server [[operating system]] for [[network-attached storage]] (NAS).<ref>{{Cite web |last=Posey |first=Brien |date=2003-11-03 |title=Microsoft does NAS with Windows Storage Server 2003 |url=https://www.techrepublic.com/article/microsoft-does-nas-with-windows-storage-server-2003/ |access-date=2023-01-14 |website=TechRepublic |language=en-US}}</ref> Launched in 2003 at [[Storage Decisions]] in Chicago, it is optimized for use in file and print sharing and also in [[storage area network]] (SAN) scenarios. It is only available through [[Original equipment manufacturer]]s (OEMs).<ref>{{Cite web |date=2003-09-10 |title=Microsoft Windows Storage Server 2003 Is Now Available, Offering Customers Dependability, Seamless Integration and Great Economics |url=https://news.microsoft.com/2003/09/10/microsoft-windows-storage-server-2003-is-now-available-offering-customers-dependability-seamless-integration-and-great-economics/ |access-date=2023-01-14 |website=Stories |language=en-US}}</ref> Unlike other Windows Server 2003 editions that provide file and printer sharing functionality, Windows Storage Server 2003 does not require any CAL.<ref>{{Cite web |date=2003-11-25 |title=What You Need to Know About Windows Storage Server 2003 |url=https://www.itprotoday.com/windows-8/what-you-need-know-about-windows-storage-server-2003 |access-date=2023-01-14 |website=ITPro Today: IT News, How-Tos, Trends, Case Studies, Career Tips, More |language=en}}</ref>

Windows Storage Server 2003 NAS equipment can be ''headless'', which means that they are without any monitors, keyboards or mice, and are administered remotely.<ref>{{Cite book |title=1. Introducing Windows Server 2003 – Learning Windows Server 2003 [Book] |url=https://www.oreilly.com/library/view/learning-windows-server/0596006241/ch01.html |access-date=2023-01-14 |website=www.oreilly.com |isbn=978-0-596-00624-2 |language=en}}</ref> Such devices are plugged into any existing [[Internet Protocol|IP]] network and the storage capacity is available to all users. Windows Storage Server 2003 can use [[RAID]] arrays to provide [[data redundancy]], [[fault-tolerance]] and high performance.<ref>{{Cite book |title=1. Introducing Windows Server 2003 – Learning Windows Server 2003 [Book] |url=https://www.oreilly.com/library/view/learning-windows-server/0596006241/ch01.html |access-date=2023-01-14 |website=www.oreilly.com |isbn=978-0-596-00624-2 |language=en}}</ref> Multiple such NAS servers can be clustered to appear as a single device, which allows responsibility for serving clients to be shared in such a way that if one server fails then other servers can take over (often termed a [[failover]]) which also improves fault-tolerance.<ref>{{Cite web |date=2010-10-28 |title=How to configure a failover cluster using Microsoft Windows 2003/2008 |url=https://www.starwindsoftware.com/resource-library/how-to-configure-a-failover-cluster-using-microsoft-windows-20032008/ |access-date=2023-01-14 |website=Resource Library}}</ref>

Windows Storage Server 2003 can also be used to create a [[Storage Area Network]], in which the data is transferred in terms of chunks rather than files, thus providing more granularity to the data that can be transferred. This provides higher performance to [[database]] and [[OLTP|transaction processing]] applications. Windows Storage Server 2003 also allows NAS devices to be connected to a SAN.{{Citation needed|date=January 2023}}

Windows Storage Server 2003 led to a second release named Windows Storage Server 2003 R2. This release adds file-server performance optimization, Single Instance Storage (SIS), and index-based search. Single instance storage (SIS) scans storage volumes for duplicate files, and moves the duplicate files to the common SIS store. The file on the volume is replaced with a link to the file. This substitution reduces the amount of storage space required, by as much as 70%.<ref name="StorageServerITPro">{{cite web|url=https://www.itprotoday.com/windows-8/storage-server-r2-boasts-search-and-file-access-improvements|title=Storage Server R2 Boasts Search and File-Access Improvements|website=[[IT Pro]]|first=David|last=Chernicoff|date=April 17, 2006|access-date=September 2, 2006|archive-url=https://web.archive.org/web/20120404041721/http://www.windowsitpro.com/article/windows-server-2003/storage-server-r2-boasts-search-and-file-access-improvements|archive-date=April 4, 2012|url-status=live}}</ref>

Windows Storage Server 2003 R2 provides an index-based, full-text search based on the indexing engine already built into Windows server.<ref name="StorageServerITPro" /> The updated search engine speeds up indexed searches on network shares. This edition also provides filters for searching many standard file formats, such as [[ZIP (file format)|ZIP archives]], [[AutoCAD|AutoCAD models]], [[XML|XML documents]], [[MP3|MP3 audio files]], [[PDF|PDF documents]], and all [[Microsoft Office]] file formats.

Windows Storage Server 2003 R2 includes built in support for Windows SharePoint Services and Microsoft SharePoint Portal Server, and adds a Storage Management snap-in for the Microsoft Management Console. It can be used to manage storage volumes centrally, including [[Distributed File System (Microsoft)|DFS]] shares, on servers running Windows Storage Server R2.

Windows Storage Server 2003 R2 can be used as an [[iSCSI]] target with standard and enterprise editions of Windows Storage Server 2003 R2, incorporating [[WinTarget]] iSCSI technology which Microsoft acquired in 2006 by from StringBean software.<ref>{{cite web |first=Nicholas |last=Kolakowski |url=http://www.eweek.com/article2/0,1759,1933870,00.asp |archive-url=https://archive.today/20130122195959/http://www.eweek.com/article2/0,1759,1933870,00.asp |url-status=dead |archive-date=January 22, 2013 |title=HP TouchPad Needs 6 to 8 Weeks for Additional Shipments |publisher=Eweek.com |date=2011-09-07 |access-date=2013-01-09 }}</ref><ref>{{cite web|url=http://www.microsoft.com/windowsserversystem/wss2003/productinformation/newsreviews/stringbean.mspx |title=Microsoft Corporation Acquires WinTarget Technology from String Bean Software |publisher=Microsoft.com |access-date=November 22, 2011}}</ref> This will be an add-on feature available for purchase through OEM partners as an iSCSI feature pack, or is included in some versions of WSS as configured by OEMs.

Windows Storage Server 2003 can be promoted to function as a domain controller; however, this edition is not licensed to run directory services. It can be joined to an existing domain as a member server.<ref name="storageserverfaq">{{cite web|url=http://www.microsoft.com/windowsserversystem/wss2003/productinformation/FAQ/default.mspx|title=Windows Storage Server 2003 R2 – Frequently Asked Questions|publisher=Microsoft}}</ref>

====Features====
* '''[[Distributed File System (Microsoft)|Distributed File System]] (DFS)''': Allows multiple [[network share]]s to be aggregated as a virtual file system.
* Support for '''[[Storage area network|SAN]]''' and '''[[iSCSI]]''': Allows computers to connect to a Storage Server over the [[LAN]], without the need for a separate [[fibre channel]] network, thus a [[Storage Area Network]] can be created over the [[LAN]] itself. iSCSI uses the [[SCSI]] protocol to transfer data as a block of bytes, rather than as a file. This increases performance of the Storage network in some scenarios, such as using a database server.
* '''Virtual Disc Service''': Allows [[Network-attached storage|NAS]] devices, [[RAID]] devices and SAN shares to be exposed and managed as if they were normal hard drives.
* '''JBOD systems''': [[JBOD]] (''Just a bunch of discs'') systems, by using VDS, can manage a group of individual storage devices as a single unit. There is no need for the storage units to be of the same maker and model.
* Software and Hardware '''RAID''': Windows Storage Server 2003 has intrinsic support for hardware implementation of [[RAID]]. In case hardware support is not available, it can use software enabled RAID. In that case, all processing is done by the OS.
* '''Multi Path IO (MPIO)''': It provides an alternate connection to IO devices in case the primary path is down.

====Editions====
Windows Storage Server 2003 R2 was available in the following editions:<ref>{{Cite web |title=Introduction to Per Core Licensing and Basic Definitions |url=https://download.microsoft.com/download/3/d/4/3d42bdc2-6725-4b29-b75a-a5b04179958b/percorelicensing_definitions_vlbrief.pdf |date=April 2017 |access-date=2023-03-12}}</ref><ref>{{Cite web |title=Microsoft Windows Storage Server 2003 R2 x64 Editions Important Information |url=https://dl.dell.com/manuals/all-products/esuprt_electronics/esuprt_software/esuprt_operating_system/ms-win-storage-srvr-2003-r2-x64-edtn_reference%20guide_en-us.pdf |date=September 2006 |access-date=2023-01-14}}</ref>
{| class="wikitable" style="margin:auto; text-align:center;"
|-
!
! Express
! Workgroup
! Standard
! Enterprise
|-
| Number of physical CPUs<ref group=lower-roman name="CPUZ" />
| colspan="2" | 1 || 1–4 || 1–64
|-
| x64 variants available
| {{Yes}} || {{Yes}} || {{Yes}} || {{Yes}}
|-
| Numbers of disk drives
| 2 || 4 || colspan="2" rowspan="2" | Unlimited
|-
| NICs
| 1 || 2 
|-
| Print service
| {{No}} || {{Yes}} || {{Yes}} || {{Yes}}
|-
| CALs required
| {{No}} || {{No}} || {{No}} || {{No}}
|-
|Clustering
| {{No}} || {{No}} || {{No}} || {{Yes}}
|-
| iSCSI target support
| {{Optional}} || {{Optional}} || {{Optional}} || {{Optional}}
|}
{{Reflist |group=lower-roman |refs=
<ref name="CPUZ" group=lower-roman>Microsoft defines a physical CPU/processor as a single socket/node on the systemboard. For O/S licensing purposes, a dual-socket single-core (Intel Pentium/4 Xeon, AMD Athlon/64) system counts as a total of 2 processors, whereas a single-socket quad-core CPU (such as AMD's Opteron and Intel's Xeon) counts as 1 processor. Microsoft's policy has no bearing on how third-party software vendors (such as Oracle) administer CPU licensing for its server applications.</ref>
}}
Windows Unified Data Storage Server is a variant of Windows Storage Server 2003 R2 with iSCSI target support standard, available in only the standard and enterprise editions.<ref>Microsoft Windows Unified Data Storage Server 2003 whitepaper – Microsoft Corporation (October 2006)</ref>

===Windows Small Business Server===
{{Main|Windows Small Business Server}}

Windows Small Business Server (SBS) is a [[software suite]] which includes Windows Server and additional technologies aimed at providing a small business with a complete technology solution.

The Standard edition of SBS includes [[Microsoft Remote Web Workplace]], [[Windows SharePoint Services]], [[Microsoft Exchange Server]], Fax Server, [[Active Directory]], a basic [[firewall (computing)|firewall]], [[DHCP server]] and [[network address translation]] capabilities. The Premium edition of SBS adds [[Microsoft SQL Server]] 2000 and [[Microsoft ISA Server]] 2004.

SBS has its own type of CAL that is different and costs slightly more than CALs for the other editions of Windows Server 2003. However, the SBS CAL encompasses the user CALs for Windows Server, Exchange Server, SQL Server and ISA Server, and hence is less expensive than buying all other CALs individually.

SBS has the following design limitations, mainly affecting Active Directory:<ref>{{cite web|url=http://www.microsoft.com/windowsserver2003/sbs/techinfo/overview/generalfaq.mspx#EIBAA|title=Windows Small Business Server 2003 R2: Frequently Asked Questions|publisher=Microsoft|date=July 11, 2006|access-date=September 2, 2006}}</ref>

* Only one computer in a [[Windows Server domain]] can be running SBS
* SBS must be the root of the [[Active Directory#Forests, trees, and domains|Active Directory forest]]
* SBS cannot trust any other domains
* SBS is limited to 75 users or devices depending on the type of CAL
* SBS is limited to a maximum of 4&nbsp;GB of RAM
* SBS domains cannot have any child domains
* [[Terminal Services]] only operates in [[remote administration]] mode on SBS, meaning that only two simultaneous RDP sessions are allowed<ref>{{cite web|url=http://www.microsoft.com/WindowsServer2003/sbs/evaluation/faq/licensing.mspx|title=Licensing – Windows Small Business Server 2003 R2: Frequently Asked Questions|publisher=Microsoft|access-date=September 2, 2006}}</ref>

To remove the limitations from an instance of SBS and upgrade to regular Windows Server, Exchange Server, SQL and ISA Server, there is a Windows Small Business Server 2003 R2 Transition Pack.<ref>{{Cite web |url=http://www.microsoft.com/technet/prodtechnol/sbs/2003/support/documentation/75a8c83b-24b8-4de4-928b-9e01e5b732b3.mspx?mfr=true |title=Windows Server 2003<!-- Bot generated title --> |website=[[Microsoft]] |access-date=2006-12-07 |archive-date=2020-10-03 |archive-url=https://web.archive.org/web/20201003223049/http://www.microsoft.com/technet/prodtechnol/sbs/2003/support/documentation/75a8c83b-24b8-4de4-928b-9e01e5b732b3.mspx?mfr=true |url-status=live }}</ref>

===Windows Home Server===
{{Main|Windows Home Server}}
[[Windows Home Server]] (WHS) is an operating system from Microsoft based on Windows Small Business Server 2003 SP2.<ref>{{Cite web |date=2010-11-18 |title=History Lesson, Part 2: Windows Home Server {{!}} Bruceb Consulting |url=https://www.bruceb.com/2010/11/history-lesson-part-2-windows-home-server/ |access-date=2023-01-14 |language=en-US}}</ref> Windows Home Server was announced on January 7, 2007, at the [[Consumer Electronics Show]] by [[Bill Gates]] and is intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups, and remote access.<ref>{{Cite web |date=2007-01-08 |title=Bill Gates Unveils Windows Home Server at the 2007 International Consumer Electronics Show |url=https://news.microsoft.com/2007/01/08/bill-gates-unveils-windows-home-server-at-the-2007-international-consumer-electronics-show/ |access-date=2023-01-14 |website=Stories |language=en-US}}</ref>

Windows Home Server began shipment to OEMs on September 15, 2007.<ref>{{cite news | last=Hill | first=Brandon | title=Windows Home Server Systems to Ship 15 September | date=August 22, 2007 | website=DailyTech.com | publisher=DailyTech | url=http://www.dailytech.com/Windows+Home+Server+Systems+to+Ship+September+15/article8507.htm | access-date=October 11, 2007 | archive-date=October 12, 2007 | archive-url=https://web.archive.org/web/20071012054557/http://www.dailytech.com/Windows+Home+Server+Systems+to+Ship+September+15/article8507.htm | url-status=dead }}</ref>

===Windows Server for Embedded Systems===
{{Main|Windows Embedded}}
Windows Server 2003 for Embedded Systems replaced "Windows 2000 Server for Embedded Systems". Intended use was for building firewall, VPN caching servers and similar appliances.<ref>{{cite web|url=http://zoliherczeg.files.wordpress.com/2010/03/2-windows-server-with-embedded-licensing.pptx |title=Windows Server with Embedded Licensing |website=Zoliherczeg.files.wordpress.com |access-date=2017-01-27}}</ref> Variants were available with "Server Appliance Software" and with "Microsoft Internet Security and Acceleration Server" <ref>{{cite web |url=http://faq.10zigsupport.com/downloads/Distribution%2520End%2520Dates%2520Table%252005262011.docx |title=Archived copy |access-date=2014-06-15 |url-status=dead |archive-url=https://web.archive.org/web/20141024141938/http://faq.10zigsupport.com/downloads/Distribution%20End%20Dates%20Table%2005262011.docx |archive-date=2014-10-24 }}</ref>

Availability of the original version ended May 28, 2003. Availability of R2 ended March 5, 2006. End of extended support was July 14, 2015 (all variants except Storage Server<ref name=SS03 />), and End of Licence was May 28, 2018 (R2 and original).<ref>{{cite web|url=http://www.microsoft.com/windowsembedded/en-us/product-lifecycles.aspx |title=Product Lifecycles & Support |publisher=Microsoft |access-date=2017-01-27}}</ref> The End of Licence date is the last date that OEM's may distribute systems using this version. All variants continued to receive Critical security updates until the end of extended support:<ref>{{cite web |first=Dave |last=Massy |url=https://blogs.msdn.microsoft.com/windows-embedded/2014/02/17/what-does-the-end-of-support-of-windows-xp-mean-for-windows-embedded/ |title=What does the end of support of Windows XP mean for Windows Embedded? |website=Windows Embedded Blog |date=February 17, 2014}}</ref>

Release 2 for Embedded Systems was available in 32 and 64 bit variants, Standard (1–4 CPU) and Enterprise (1–8 CPU):<ref>{{cite web |url=http://www.mdspacific.com/product/productView.asp?page=1&cate=001007&idx=9 |title=Embedded Total Solution – Windows Embedded OS &#124;Industrial Storages and Motherboards&#124; Cloning and Recovery Solutions Development, Analysis and Testing Solutions |publisher=MDS Pacific |access-date=2017-01-27 |archive-date=2014-08-21 |archive-url=https://web.archive.org/web/20140821212626/http://www.mdspacific.com/product/productView.asp?page=1&cate=001007&idx=9 |url-status=dead }}</ref>

===Windows XP Professional x64 Edition===
{{Main|Windows XP Professional x64 Edition}}
Windows XP Professional x64 Edition was released less than a month after Windows Server 2003 SP1,<ref>{{Cite web |last=GitHub-Name |title=Windows XP – Microsoft Lifecycle |url=https://learn.microsoft.com/en-us/lifecycle/products/windows-xp |access-date=2023-01-14 |website=learn.microsoft.com |language=en-us}}</ref> and used the same kernel and source code tree. While many features of the 32-bit variant of Windows XP were brought over into Windows XP Professional x64 Edition, other limitations imposed by constraints such as only supporting 64-bit drivers, and support for 16-bit programs being dropped led to incompatibilities with the 32-bit Windows XP editions available. It later received a Service Pack update as part of the release of Windows Server 2003 SP2.{{Citation needed|date=January 2023}}

==Updates==

===Service Pack 1===
On March 30, 2005, Microsoft released Service Pack 1 for Windows Server 2003. Among the improvements are many of the same updates that were provided to Windows XP users with Service Pack 2. Features that are added with Service Pack 1 include:

* Security Configuration Wizard, which is a tool that allows administrators to more easily research, and make changes to, security policies.<ref>{{cite web|url=http://www.microsoft.com/windowsserver2003/technologies/security/configwiz/default.mspx|title=Security Configuration Wizard for Windows Server 2003|website=[[Microsoft]]|access-date=September 2, 2006}}</ref>
* Hot Patching, a feature made to extend Windows Server 2003's ability to take DLL, Driver, and non-kernel patches without a reboot.
* IIS 6.0 Metabase Auditing, a feature allows the tracking of metabase edits.<ref>{{cite web|url=http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/b5ac0be1-24b5-4e13-9d61-485e28657f83.mspx|title=Metabase Auditing (IIS 6.0)|website=[[Microsoft]]|access-date=September 2, 2006}}</ref>
* [[Windows Firewall]], which brings many of the improvements from Windows XP Service Pack 2 to Windows Server 2003; also with the Security Configuration Wizard, it allows administrators to more easily manage the incoming open ports, as it will automatically detect and select default roles.
* Other networking improvements include support for Wireless Provisioning Services, better IPv6 support, and new protections against [[SYN flood]] TCP attacks.<ref>{{cite web|url=http://www.microsoft.com/technet/community/columns/cableguy/cg1204.mspx|title=The Cable Guy – December 2004: New Networking Features in Microsoft Windows Server 2003 Service Pack 1|publisher=Microsoft TechNet|date=December 1, 2004|access-date=September 2, 2006}}</ref>
* Post-Setup Security Updates, a panel which is shown only when the operating system is first installed. This window allows you to configure and update your server, and halts incoming connections until it is closed.
* [[Data Execution Prevention]] (DEP), a feature to add support for the [[NX bit|No Execute (NX) bit]] which helps to prevent [[buffer overflow]] exploits that are often the attack vector of Windows Server exploits.<ref>{{cite web|url=http://support.microsoft.com/kb/875352|title=A detailed description of the Data Execution Prevention (DEP) feature in Windows XP Service Pack 2, Windows XP Tablet PC Edition 2005, and Windows Server 2003 (KB 875352)|publisher=Microsoft|access-date=September 2, 2006}}</ref>
* [[Windows Media Player]] version 10
* [[Internet Explorer 6]] SV1<ref name="sv1">SV1 stands for "Security Version 1", referring to the set of security enhancements made for that release [http://blogs.msdn.com/ie/archive/2004/09/02/224902.aspx] {{Webarchive|url=https://web.archive.org/web/20100124201756/http://blogs.msdn.com/ie/archive/2004/09/02/224902.aspx|date=2010-01-24}}. This version of Internet Explorer is more popularly known as IE6 SP2, given that it is included with Windows XP Service Pack 2, but this can lead to confusion when discussing Windows Server 2003, which includes the same functionality in the SP1 update to that operating system.</ref> (e.g. 'IE6 SP2')
* Support for fixed disks bearing data organized using the [[GUID Partition Table]] system<ref>{{cite web|url=http://www.microsoft.com/whdc/device/storage/GPT_FAQ.mspx#ELD |title=Windows and GPT FAQ |publisher=Microsoft.com |date=June 15, 2011 |access-date=November 22, 2011}}</ref>

A full list of updates is available in the Microsoft Knowledge Base.<ref>{{cite web|url=http://support.microsoft.com/kb/824721|title=Windows Server 2003 Service Pack 1 list of updates (KB 824721)|publisher=Microsoft|access-date=September 2, 2006}}</ref>

===Service Pack 2===
Service Pack 2 for Windows Server 2003 was released on March 13, 2007.<ref name="roadmap">{{cite web | url=http://www.microsoft.com/windows/lifecycle/servicepacks.mspx | title=Windows Service Pack Road Map | date=July 10, 2008 | access-date=September 15, 2008 | publisher=Microsoft }}</ref> The release date was originally scheduled for the first half of 2006.<ref name="roadmap"/> On June 13, 2006, Microsoft made an initial test version of Service Pack 2 available to Microsoft Connect users, with a build number of 2721. This was followed by build 2805, known as Beta 2 Refresh. The final build is 3790.

Microsoft has described Service Pack 2 as a "standard" service pack release containing previously released security updates, hotfixes, and reliability and performance improvements.<ref>{{cite web |url=https://blogs.technet.microsoft.com/windowsserver/2006/08/01/windows-server-2003-and-xp-x64-editions-service-pack-2/ |title=Windows Server 2003 and XP x64 Editions Service Pack 2 |first=Ward |last=Ralston |date=August 1, 2006 |work=Windows Server Blog |publisher=[[Microsoft]]}}</ref> In addition, Service Pack 2 contains [[Microsoft Management Console]] 3.0, Windows Deployment Services (which replaces [[Remote Installation Services]]), support for [[Wi-Fi Protected Access|WPA2]], and improvements to [[IPsec]] and MSConfig. Service Pack 2 also adds ''Windows Server 2003 Scalable Networking Pack'' (SNP),<ref>{{cite web|title=Windows Server 2003 gets second update | website = [[ZDNet]] | url = https://www.zdnet.com/article/windows-server-2003-gets-second-update/ | access-date =March 13, 2007}}</ref> which allows hardware acceleration for processing network packets, thereby enabling faster throughput. SNP was previously available as an out-of-band update for Windows Server 2003 Service Pack 1.

==Windows Server 2003 R2==
<!--CAUTION: Multiple articles, multiple redirects and at least one navbox link to this anchor. Its name should not be changed without updating backlinks.-->
'''Windows Server 2003 R2''' is an updated release of Windows Server 2003. It was released to manufacturing on December 6, 2005 for IA-32 and x64 platforms, but not for [[IA-64]].<ref name="R2informationweek">{{cite web |url=https://www.informationweek.com/software/new-version-of-windows-server-is-on-the-way |archive-url=https://web.archive.org/web/20071212003046/http://www.informationweek.com/showArticle.jhtml?articleID=174901192 |archive-date=2007-12-12 | title=New Version Of Windows Server Is On The Way |work=[[InformationWeek]] | date=6 December 2005 |publisher=[[UBM plc|UBM]] | access-date=May 30, 2022|url-status=live}}</ref> It was succeeded by [[Windows Server 2008]].

New features of Windows Server 2003 R2 include:<ref>{{cite web|last1=Otey|first1=Michael|title=New Features in Windows Server 2003 R2|url=https://www.itprotoday.com/windows-78/new-features-windows-server-2003-r2|website=[[IT Pro]]|publisher=[[Penton (company)|Penton]]|date=24 April 2006|archive-url=https://web.archive.org/web/20220531005317/https://www.itprotoday.com/windows-78/new-features-windows-server-2003-r2|archive-date=31 May 2022|url-status=live}}</ref>
* [[.NET Framework 2.0]], which replaces the [[.NET Framework 1.0]] included with the standard releases
* [[Active Directory Federation Services]], a single sign-on solution for Active Directory Services
* [[Microsoft Management Console]] version 3.0. Additionally, several new snap-ins are included:
** Print Management Console, for managing [[print server]]s
** File Server Resource Manager, for managing [[disk quota]]s on [[file server]]s
** Storage Manager for SANs, for managing [[Logical unit number|LUNs]] 
* A new version of [[Distributed File System (Microsoft)|Distributed File System]] that includes remote differential compression technology
* [[Microsoft Virtual Server]] 2005, a [[hypervisor]] and the precursor to [[Hyper-V]]
* [[Windows Services for UNIX]], a UNIX environment for Windows

Windows Server 2003 R2 was distributed in two [[CD]]s, one containing a copy of Windows Server 2003 with Service Pack 1 included and another containing a host of optionally-installed new features needed for Windows Server 2003 R2 installation, similar to that of [[Microsoft Plus! for Windows 95]].<ref name="Winserver 2k3R2 installation help">{{cite web |url=https://technet.microsoft.com/en-US/library/cc786375(v=ws.10).aspx| title=Windows Server 2003 R2 installation help | date=8 October 2009 |publisher=Microsoft | access-date=February 23, 2013}}</ref>

==Support lifecycle==
On July 13, 2010, Windows Server 2003's mainstream support expired and the extended support phase began. During the extended support phase, Microsoft continued to provide security updates; however, free technical support, warranty claims, and design changes are no longer being offered.<ref name="lifecycle">{{cite web | url = http://support.microsoft.com/lifecycle/?c2=1163 | title = Microsoft Support Lifecycle | work = Support
| publisher = Microsoft | access-date =April 11, 2014}}</ref> Extended support lasted until July 14, 2015.<ref name="lifecycle"/> Mainstream support for Small Business Server edition ended on April 12, 2011 and extended support ended on April 12, 2016. Mainstream support for Storage Server edition ended on October 11, 2011 and extended support ended on October 9, 2016.

Although Windows Server 2003 is unsupported, Microsoft released an emergency security patch in May 2017 for the OS as well as other unsupported versions of Windows (including [[Windows XP]], [[Windows Vista]] and [[Windows 7]] RTM without a service pack), to address a vulnerability that was being leveraged by the [[WannaCry ransomware attack]].<ref name="verge-highlyunusual">{{cite web|title=Microsoft issues 'highly unusual' Windows XP patch to prevent massive ransomware attack|url=https://www.theverge.com/2017/5/13/15635006/microsoft-windows-xp-security-patch-wannacry-ransomware-attack|website=The Verge|date=13 May 2017 |publisher=Vox Media|access-date=13 May 2017}}</ref><ref name="ms-wannacrypatch">{{cite web|title=Customer Guidance for WannaCrypt attacks|date=13 May 2017 |url=https://blogs.technet.microsoft.com/msrc/2017/05/12/customer-guidance-for-wannacrypt-attacks/|publisher=[[Microsoft]]|access-date=13 May 2017}}</ref>

In 2020, Microsoft announced that it would disable the Windows Update service for SHA-1 endpoints for older Windows versions. Since Windows Server 2003 did not get an update for SHA-2, Windows Update Services are no longer available on the OS as of late July 2020.<ref>{{cite web|title=Windows Update SHA-1 based endpoints discontinued for older Windows devices|url=https://support.microsoft.com/en-us/topic/windows-update-sha-1-based-endpoints-discontinued-for-older-windows-devices-10b58bd9-5ba2-b23d-498b-139ce5c709af|access-date=April 6, 2021|website=support.microsoft.com|archive-date=April 17, 2021|archive-url=https://web.archive.org/web/20210417045726/https://support.microsoft.com/en-us/topic/windows-update-sha-1-based-endpoints-discontinued-for-older-windows-devices-10b58bd9-5ba2-b23d-498b-139ce5c709af|url-status=live}}</ref> As of March 2024, many of the old updates for Windows Server 2003 are available on the [[Microsoft Update Catalog]].<ref>{{cite web|title=Microsoft Update Catalog|url=https://www.catalog.update.microsoft.com/Search.aspx?q=windows%20server%202003|access-date=March 6, 2025|website=www.catalog.update.microsoft.com|archive-date=July 8, 2024|archive-url=https://web.archive.org/web/20240708183625/https://www.catalog.update.microsoft.com/Search.aspx?q=windows%20server%202003|url-status=live}}</ref> A third-party tool named Legacy Update allows previously released updates for Windows Server 2003 to be installed from the Update Catalog.<ref>{{Cite web |last=Cunningham |first=Andrew |date=2023-07-10 |title=Windows 95, 98, and other decrepit versions can grab online updates again |url=https://arstechnica.com/gadgets/2023/07/windows-95-98-and-other-decrepit-versions-can-grab-online-updates-again/ |access-date=2024-08-05 |website=[[Ars Technica]] |language=en-us}}</ref>

{{Timeline Windows Server 2003}}

== Source code leak ==
On September 23, 2020, the [[Windows XP Service Pack 1]] and Windows Server 2003 source code was leaked onto the [[imageboard]] [[4chan]] by an unknown user. Anonymous users managed to compile the Windows Server 2003 source code, as well as a Twitter user who posted videos of the process on YouTube proving that the code was genuine,<ref>{{Cite web|last=Cimpanu|first=Catalin|title=Windows XP leak confirmed after user compiles the leaked code into a working OS|url=https://www.zdnet.com/article/windows-xp-leak-confirmed-after-user-compiles-the-leaked-code-into-a-working-os/|access-date=2020-10-01|website=ZDNet|language=en}}</ref> but [[YouTube copyright strike|was removed from the platform]] on copyright grounds by Microsoft. The leak was incomplete as it was missing the [[Winlogon]] source code and some other components.<ref>{{Cite web|last=Warren|first=Tom|date=2020-09-25|title=Windows XP source code leaks online|url=https://www.theverge.com/2020/9/25/21455655/microsoft-windows-xp-source-code-leak|access-date=2020-10-01|website=The Verge|language=en}}</ref><ref>{{Cite web|last=September 2020|first=Paul Alcorn 30|title=Windows XP Source Code Leaked, Posted to 4chan (Update, It Works)|url=https://www.tomshardware.com/news/working-windows-xp-source-code-posted-to-4chan-update|access-date=2020-10-01|website=Tom's Hardware|date=30 September 2020 |language=en}}</ref> The original leak itself was spread using [[Magnet URI scheme|magnet link]]s and torrent files whose payload originally included Server 2003 and XP source code and which was later updated by additional files among which were previous leaks of Microsoft products, its patents, media about [[conspiracy theories]] about [[Bill Gates]] by [[anti-vaccination movement]]s and an assortment of PDF files on different topics.<ref>{{Cite web|title=Windows XP Source Code Leaked By Apparent Bill Gates Conspiracist|url=https://gizmodo.com/windows-xp-source-code-leaked-by-apparent-bill-gates-co-1845181128|access-date=2020-10-01|website=Gizmodo|date=25 September 2020 |language=en-us}}</ref>

Microsoft issued a statement stating that it was investigating the leaks.<ref>{{Cite web|last=September 2020|first=Paul Alcorn 30|title=Windows XP Source Code Leaked, Posted to 4chan (Update, It Works)|url=https://www.tomshardware.com/news/working-windows-xp-source-code-posted-to-4chan-update|access-date=2021-03-26|website=Tom's Hardware|date=30 September 2020 |language=en}}</ref><ref>{{Cite web|date=2020-09-25|title=The Windows XP and Windows Server 2003 source code leaks online|url=https://grahamcluley.com/download-windows-xp-source-code-leaks/|access-date=2021-03-26|website=Graham Cluley|language=en-GB}}</ref><ref>{{Cite web|date=2020-09-28|title=Windows XP source code leaked online|url=https://www.computing.co.uk/news/4020805/windows-xp-source-code-leaked|access-date=2021-03-26|website=www.computing.co.uk|language=en}}</ref>

On April 2, 2025, a user managed to build <code>[[ntoskrnl.exe]]</code> using [[Clang]] and [[LLVM|LLD]] for the first time, rather than Microsoft's [[Microsoft Visual C++|MSVC]] compiler.<ref>{{Cite web |date=2025-04-02 |title=Release first ever build of real nt source code with clang · MobSlicer152/ntkrnl |url=https://github.com/MobSlicer152/ntkrnl/releases/tag/clang1 |access-date=2025-04-02 |website=www.github.com/MobSlicer152/ntkrnl |language=en}}</ref>

==See also==
* [[BlueKeep (security vulnerability)]]
* [[Comparison of Microsoft Windows versions]]
* [[Comparison of operating systems]]
* [[History of Microsoft Windows]]
* [[List of operating systems]]
* [[Microsoft Servers]]

==References==
{{Reflist|30em}}

==External links==
* [https://technet.microsoft.com/windowsserver/bb512919.aspx Windows Server 2003] on Microsoft TechNet
* [https://technet.microsoft.com/windowsserver/bb405947.aspx Windows Server 2003 Downloads] on Microsoft TechNet
* [http://blogs.technet.com/winserverperformance/ Windows Server Performance Team Blog] {{Webarchive|url=https://web.archive.org/web/20100504044406/http://blogs.technet.com/winserverperformance/ |date=2010-05-04 }}
* [http://lyle.smu.edu/~mhd/7343f06/casecomp.ppt Kernel comparison with Linux 2.6] by David Solomon, [[Mark Russinovich]], and Andreas Polze <!-- note: the first slide says Windows XP, but this was made in 2006, and thorough the material they refer to the 2003 kernel improvements quite a few times -->

{{History of Windows}}

{{Authority control}}

[[Category:2003 software]]
[[Category:Products and services discontinued in 2015]]
[[Category:Windows Server|2003]]
[[Category:IA-32 operating systems]]
[[Category:X86-64 operating systems]]
[[Category:Microsoft Windows|Server 2003]]