Build list legend
|Version of Microsoft Windows|
|OS family||Windows NT|
|Codename||Windows Server 8|
Small Business Server "8" (Essentials)
2026-10-13 (with Extended Security Updates)
|Windows Server 2008 R2|
|Windows Server 2012 R2|
Windows Server 2012 is the server counterpart of Windows 8. It replaces Windows Server 2008 R2 and was replaced by Windows Server 2012 R2. It reached RTM on 1 August 2012 and was released on 4 September of that year. Support for the IA-64 architecture was dropped with this release.
This is the first version of Windows Server to drop support for processors without NX, as running on these processors will cause an
UNSUPPORTED_PROCESSOR bugcheck upon boot. It is also the last version of Windows Server to support processors without the CMPXCHG16b, PrefetchW and LAHF/SAHF instructions.
Notably, it is the first release of Windows Server to include an Essentials edition, which contains all features and functionalities of the former Home Server and Small Business Server product lines. It is also the first server release of Windows to drop the traditional Service Pack mechanism in favor of releasing updates in smaller chunks on a continual basis. It is the last version to support upgrade paths from Windows Server 2008.
There are four major editions of Windows Server 2012: