Why does Windows 7 have a seven in its name?
Windows 7 reports its version as:
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
And by my reckoning it was preceded by:
- Windows 1.0
- Windows 2.0
- Windows 3.0 & 3.1
- Windows 95
- Windows 98
- Windows Millenium (the Windows that never was)
- Windows NT 1
- Windows NT 2
- Windows NT 3
- Windows NT 4
- Windows 2000
- Windows XP
- Windows Vista (how appropriate)
- Windows 7
Assuming I haven't missed any, that makes Windows 7 the 14th major version of Windows. Even if you omit NT 1 - 4, it's still the 10th major consumer version.
Does anyone know why it was branded "7"?
Windows 7 is named thusly, because Vista was version 6.0. Windows 7 is versioned 6.1 to maintain support for applications that use the major version number for testing their compatibility level.
Read more from the Windows blog and here (which Nick linked to as well).
It is explained here Why 7
That brings us to Windows Vista, which is 6.0. So we see Windows 7 as our next logical significant release
Pure Marketing.
Windows 1,2,3,95,98 and ME don't count anymore, it's the NT Line now.
NT 1 and 2 never existed, NT 3.1 and 3.5.1 were the first ones, named after Windows 3.1 but not based on them.
From there, version numbers split.
After NT 3 came NT 4, then NT 5 (Windows 2000), NT 5.1 (Windows XP), NT 6 (Vista) and NT 6.1 (Win7).
As said, Win7 is internally 6.1 for compatibility reasons (and possibly because just as XP was only a mid-sized upgrade to 2000, 7 is only a medium sized upgrade to Vista. NT 4 > 2000 > Vista were big architectural upgrades).
It was initially planned as a full 7.0, and less-than stellar Vista performance led to an earlier release. The name was a long-rumored and longer-awaited set of features. Basically, as far as the "real" numbering goes, all of the Windows dot releases are similar-kernel, but mostly GUI or app additions.
For trivia, XP x64 is NT 5.2 :)
I think it's because of the kernel version, it's 6.1 as you pointed out. Windows 6.1 would sound bad. So they are using Windows 7. Why they hadn't increased kernel version to 7.0 is hard to say, but I think it's because of they don't changed very much in the kernel compared to Vista.