Windows Server 2008 Build 6003 represents a technical milestone in the sunset years of one of Microsoft's most enduring server operating systems. While not a new feature release in the traditional sense, Build 6003 is a critical administrative update that allows Windows Server 2008 Service Pack 2 (SP2)
For trivia night: The only other modern Windows version to get a post-EOL build number bump was for similar servicing stack reasons. But Server 2008’s jump from 6002 to 6003 remains a unique quirk. windows server 2008 build 6003