You may be wondering why the code name for the new version of Windows to be released in 2010 goes by the code name of "Windows 7". Surely there have been more versions of Windows than that preceding that version.
Well there have been more versions of Windows - Windows 1, Windows 2, Windows 3.0, Windows 3.1, Windows 95, Windows 98, Windows 98 SE, and Windows ME don't count though because they are actually a completely different sequence from the current one because all of those are variants of DOS.
The current Microsoft Operating system has gone by a variety of different names during its life and it just happens that windows 7 is in fact the seventh version of this operating system. The versions of this operating system are as follows.
Of course I am only assuming that this is the reason why they have called it Windows 7 since this is the list of the actual versions of the current windows operating system to which the new version belongs.