Why is Windows 7 so called?
I was wondering why Windows 7 and Windows 8 are numbered as such, if there are correspondences to "Windows 1, ..., 6"?
The naming of Windows 7 is explained in the Windows Team Blog's announcement of Windows 7:
Windows 8 is still referred to by Microsoft as a code name. The official name of the product has not been announced. It might remain Windows 8, or it could change - we don't know though, and there are no objective sources to tell us one way or the other.
No one knows for sure, not even Microsoft
As you can see a few are missing from the list, Win95, 98, ME
1st: Windows NT 3.1
2nd: Windows NT 3.5
3rd: Windows NT 4.0
4th: Windows 2000 (5.0)
5th: Windows XP (5.1)
6th: Windows Vista (6.0)
And finally 7th: Windows 7 (6.1) (Windows 7 is the 7th major version in the desktop NT line)