Why Does Windows 7 Think It's Windows 6.1?
Posted by: Stephen Wildstrom on October 29

Microsoft is a bit schizoid about Windows 7. On the one hand, it of course wants to promote it as something new and different. But it is also making a big deal of its continuity with Vista.
This dissonance shows up in a curious way. The internal version number of Windows 7 is 6.1, or to be precise, 6.1.6801 in the Milestone 3 version I am testing. Vista with Service Pack 1 is version 6.0.6001.
Microsoft developers have a ready explanation for the phenomenon. Many programs check the version number of the operating system and will not install if the number falls outside a specified range. Microsoft insists that virtually all programs that run on Vista will run without alteration of Windows 7 and it doesn't want installations to bomb just because of a failed version number check. So what is officially known as the "major version number" was kept at 6.
Of course, this bit of version number legerdemain suggestions that the difference between Vista and Windows 7 really is only skin deep. But most of the problems that have plagued Vista are also only skin deep and can be fixed without tearing out the heart of the code. Still, ity does raise the question of whether Windows 7 might better be called Vista Second Edition (remember Windows 98 SE?) were Microsoft less anxious to shed itself of the tainted Vista brand.
