Similarly, Windows 2000 and XP identify as NT5.0 and 5.1 respectively, and Windows Vista/7/8/8.1 identify as NT6.0, 6.1, 6.2, and 6.3 respectively.
Incidentally, this is also why drivers often are cross-compatible along certain Windows versions.
[1]: https://en.wikipedia.org/wiki/Windows_NT#Naming
Similarly, Windows 2000 and XP identify as NT5.0 and 5.1 respectively, and Windows Vista/7/8/8.1 identify as NT6.0, 6.1, 6.2, and 6.3 respectively.
Incidentally, this is also why drivers often are cross-compatible along certain Windows versions.