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:

  1. Windows 1.0
  2. Windows 2.0
  3. Windows 3.0 & 3.1
  4. Windows 95
  5. Windows 98
  6. Windows Millenium (the Windows that never was)
  7. Windows NT 1
  8. Windows NT 2
  9. Windows NT 3
  10. Windows NT 4
  11. Windows 2000
  12. Windows XP
  13. Windows Vista (how appropriate)
  14. 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"?

  • 1
    I wish ME never was, I used it for a couple of years and it stunk...
    – sound2man
    Nov 18 '10 at 21:23
  • 9
    There was no NT1 and NT2, Windows NT3 was actually NT3.1, to keep in line with Windows 3.1, and you missed out NT3.5 and Windows Server 2003 was NT5.2
    – paradroid
    Nov 18 '10 at 21:30
  • 5
    You also forgot Windows 98 Second Edition. Nov 18 '10 at 22:49
  • Maybe those who picked the name were Seinfeld fans. Nov 18 '10 at 23:57
  • 1
    @TFM: Win2K absolutely was a consumer version. Aug 3 '11 at 2:54

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).

  • 17
    Whatever they say, Windows 7 is still a minor upgrade to Vista on a technology level, even if it is significantly improved (Vista was Windows 7 beta), much in the same way XP was a minor upgrade to Win2000.
    – paradroid
    Nov 18 '10 at 21:26
  • 1
    Hey, I won't argue with that, because it's true :-).
    – user3463
    Nov 18 '10 at 21:37
  • 1
    Very similar to how, under the hood, Windows XP was version 5.1 - a small upgrade that tizzed up Windows 2000 (which was internally version 5.0). This stuff really only matters if you are a software developer. The marketing name is not the underlying version number! Nov 19 '10 at 4:42
  • 1
    This webpage is not available -- said Chrome. And concluded: ERR_CONNECTION_RESET.
    – trejder
    Jun 18 '15 at 8:50

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

  • Was about to link to that too.
    – user3463
    Nov 18 '10 at 20:51
  • 9
    -1 Your answer glosses over what the questioner wrote right at the top. That windows 7 is reporting as 6.1 Your ans had 4 votes before anyhow, so don't worry , but 4 is definitely undeserved particularly if missing out that at the beginning.
    – barlop
    Nov 18 '10 at 21:49
  • This webpage is not available -- said Chrome. And concluded: ERR_CONNECTION_RESET.
    – trejder
    Jun 18 '15 at 8:49

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).

  • 1
    The first versions of NT were not based on Win3.1, as it was a completely new operating system. It was based on IBM OS/2 if anything. It just used the same graphic user interface as Win3.1.
    – paradroid
    Nov 19 '10 at 0:14
  • 1
    @jason404 Whoops, very true. I've changed the answer.
    – Michael Stum
    Nov 19 '10 at 0:20
  • Looking at it from the NT perspective, this actually makes more logical sense than the marketing "spin" that Microsoft themselves are putting on it all... except of course that Windows 7 is really 6.1. Nov 19 '10 at 9:35
  • @Software Monkey Indeed. If they call Windows 7 7, then they should have already called Windows XP 6, which they didn't. Technically Windows 7 is the 7th NT release though: NT 3.1, 3.5, 4, 5, 5.1, 6, 6.1
    – Michael Stum
    Nov 19 '10 at 17:46

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.

  • XP is 5.1, 5.1 doesn't sound snazzy, but it still reported as that. So they called it XP. Not a different round number.
    – barlop
    Nov 18 '10 at 21:51
  • interesitng point though perhaps distinguishing the kernel number from the classical / marketting name. I guess it's a while since the marketting name has had a number. What was the kernel number for windows 3.1 and 3.11 ?
    – barlop
    Nov 18 '10 at 21:54
  • @barlop: Win3 did not have a kernel as it was just a graphic user interface on top of MS-DOS.
    – paradroid
    Nov 19 '10 at 0:21
  • @jason404 was win9x a gui on dos? you could enter bootgui=o in msdos.sys and it went to dos, though with a flash of windows which you might've been able to turn off too. if i remember right, win9x for ver command(dosver? winver? ver?), said dos 7.
    – barlop
    Nov 22 '10 at 4:13
  • I guess one might say win9x was a mix.. but interesting if there's a clear cut answer about it
    – barlop
    Nov 22 '10 at 4:13

I guess Microsoft keep the major version number as 7 to keep backward compatible with legacy programs.


It's not called "that." It's called "Windows 7."

"Windows 7" is the name Microsoft decided to give it. It's their baby, and they can call it whatever they want. It doesn't have to make sense to anyone else (Does "Vista" make sense? "Wince?").


its called a marketing tactic - Vista was so poor they could not have possibly called it Windows 6.1 or even worse Windows Vista Me...so Windows 7 makes a clear distinction that this is not Vista.

Not the answer you're looking for? Browse other questions tagged or ask your own question.