Windows Server 2008 R2 build 6801

Windows Server 2008 R2 build 6801 is the earliest available build of Windows Server 2008 R2. This build changes the branding to "Windows Server 7" and updates the boot screen after setup.

New features and changes
This build introduces a feature internally known as “drift correction”, which resolves issues related to CPU clock circuit timing that can potentially prevent services from starting up correctly. Clock drift/timing issues plague Windows Server 2008 on Haswell and newer processors from Intel, where the OS will often not boot up successfully or boot up with many services having failed to start due to drift. Hobbyists are figuring out how to port this feature to Windows Server 2008 to resolve this problem.