Comment Drivers (Score 2) 460
I thought the main reason for Windows 7 being Windows NT 6.1 was because that way they could avoid breaking driver compatibility since most of the drivers should still work between these very similar architectures.
Windows NT 6.0 - Windows Vista/Server 2008
Windows NT 6.1 - Windows 7/Server 2008 R2
Windows NT 6.2 - Windows 8/Server 2012