Windows Server 2003 Datacenter Edition

Windows Server 2003, Datacenter Edition is designed for infrastructures demanding high security and reliability. Windows Server 2003 is available for x86, Itanium, and x86-64 processors. It supports a maximum of up to 32 processors on 32-bit or 64 processors on 64-bit hardware. 32-bit architecture also limits memory addressability to 64 GB, while the 64-bit versions support up to 1 TB. Windows Server 2003, Datacenter Edition, also allows limiting processor and memory usage on a per-application basis.

Windows Server 2003 Datacenter Edition also supports Non-Uniform Memory Access. If supported by the system, Windows, with help from the system firmware creates a Static Resource Affinity Table (SRAT) that defines the NUMA topology of the system. Windows then uses this table to optimize memory accesses, and provide NUMA awareness to applications, thereby increasing the efficiency of thread scheduling and memory management.

Windows Server 2003, Datacenter Edition has better support for Storage Area Networks (SAN). It features a service which uses Windows 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.

Windows Server 2003, Datacenter Edition, also supports 8-node clustering. Clustering increases availability and fault tolerance of server installations, by distributing and replicating the service among many servers. Windows supports clustering, with each cluster having its own dedicated storage, or all clusters connected to a common Storage Area Network (SAN), which can be running on Windows as well as non-Windows Operating systems. The SAN may be connected to other computers as well.

Windows Server 2003 R2

Windows Server 2003 R2, an update of Windows Server 2003, was released to manufacturing on 6 December 2005. It is distributed on two CDs, with one CD being the Windows Server 2003 SP1 CD. The other CD adds many optionally installable features for Windows Server 2003. The R2 update was released for all x86 and x64 versions. Windows Server 2003 R2 Enterprise Edition was not released for Itanium.

Service Pack 2

Service Pack 2 for Windows Server 2003 was released on 13 March 2007. The release date was originally scheduled for the first half of 2006. On 13 June 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 latest build is the build 3959.

Microsoft has described Service Pack 2 as a "standard" service pack release containing previously-released security updates, hotfixes, and reliability and performance improvements. In addition, Service Pack 2 contains Microsoft Management Console 3.0, Windows Deployment Services (which replaces Remote Installation Services), support for WPA2, and improvements to IPsec and MSConfig. Service Pack 2 also adds Windows Server 2003 Scalable Networking Pack (SNP), 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.

As of October 2009, no further Service Packs are planned for Windows Server 2003.