This list will become a handy note if you are dealing with Microsoft System Center products especially System Center Configuration manager.

Version Number	OS Name
Microsoft Windows NT Workstation 5.1	Windows XP
Microsoft Windows NT Workstation 5.2	Windows XP x64
Microsoft Windows NT Workstation 6.0	Windows Vista
Microsoft Windows NT Workstation 6.1	Windows 7
Microsoft Windows NT Workstation 6.2	Windows 8
Microsoft Windows NT Server 4.0	Windows NT
Microsoft Windows NT Server 5.0	Windows Server 2000
Microsoft Windows NT Server 5.2	Windows Server 2003
Microsoft Windows NT Server 6.0	Windows Server 2008
Microsoft Windows NT Server 6.1	Windows Server 2008 R2
Microsoft Windows NT Server 6.2	Windows Server 2012