: The original version number for Server 2008 SP2 was 6.0.6002 [13]. Because internal revision numbers have a maximum value, Microsoft incremented the build number to 6003 (starting with KB4493471 ) to allow for continued security updates without breaking the version string [5, 13].
If you see Build 6003 on your servers, pat yourself on the back for keeping them as secure as possible – but immediately plan your move to a supported OS. Build 6003 is the end of the road, not the beginning of a new one.
The official support for the Windows Server 2008 build 6003 codebase has finally concluded as of January 13, 2026 End of Support (January 2026)
Running Build 6003 today is considered as it no longer receives regular security patches [1, 23].
: The revision portion of a Windows version string has a set decimal range. As of early 2019, the number of updates for Windows Server 2008 SP2 was approaching the maximum value allowed by this range.