How is Windows 7 the 7th version of Windows?

If you think about it Windows 7 is not the 7th version of Windows or is it.  If you look at Windows at first you start counting from Windows 1.0

Win 1.0, Win 2.0 (286), Win 3.0, Win 3.1 (Win 3.11), Win 95 (4.0), Win 98 (Win 98 SE {4.1}), Win ME (4.9)…   Well, that’s 7 already, that does not add up.

But there is something you have to realise, After Windows ME the old Windows line (DOS Based) was merged into the Professional line (NT)

Since Windows 7 is based on the Professional (NT) line lets look at it.

Now NT was not based on of the same DOS-based code like the earlier versions, instead, it is more related to the joint venture that Microsoft and IBM had with OS/2.

Win NT 3.1, Win NT 3.5 (Win NT 3.5.1), Win NT 4, Win 2000 (NT5), Win XP (5.1), Win Vista (6.0), and Windows 7 (6.1).

That’s how it adds up to 7, the code is based on that NT line.

4 replies
  1. Ed
    Ed says:

    It is worthy to note the complete code refresh that happened between XP and Vista. Before the sasser virus Microsoft would add to the code of the previous OS and recompile. This handled application comparability really well but was bad for security. (this claim can be verified on any XP machine. Open run and type ‘progman’, scary huh?) After sasser Microsoft stopped all work on project Longhorn (Vista) and wrote XP SP2, which arguably could be called XP SE. Once XP SP2 was complete Microsoft took longhorn, which was based off of XP SP1 and threw it out. They looked to Server 2003 which had already gone through a complete code refresh and started there to make windows Vista. Progman is gone, the old 3.x file manager is gone. The code refresh was a long time comming and introduced some program compatibility issues but all in all was a necessary update to answer all the calls for a more secure home OS.

    • usefulwindows
      usefulwindows says:

      There are rumors that a lot of backward compability will be taken out of Windows 8 and instead be using hyper-V for legacy support, weather or not this is true is yet to be seen.

  2. Kevin
    Kevin says:

    The very first release of Windows was Windows 1.0, the second was Windows 2.0, the third Windows 3.0. Here’s where things get a little more complicated. Following Windows 3.0 was Windows NT which was code versioned as Windows 3.1. Then came Windows 95, which was code versioned as Windows 4.0. Then, Windows 98, 98 SE and Windows Millennium each shipped as 4.0.1998, 4.10.2222, and 4.90.3000, respectively. So we’re counting all 9x versions as being 4.0. Windows 2000 code was 5.0 and then we shipped Windows XP as 5.1, even though it was a major release we didn’t want to change code version numbers to maximize application compatibility. That brings us to Windows Vista, which is 6.0. So we see Windows 7 as our next logical significant release and 7th in the family of Windows releases…There’s been some fodder about whether using 6.1 in the code is an indicator of the relevance of Windows 7. It is not. Windows 7 is a significant and evolutionary advancement of the client operating system. It is in every way a major effort in design, engineering and innovation. The only thing to read into the code versioning is that we are absolutely committed to making sure application compatibility is optimized for our customers.


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