According to the latest StatCounter data, Windows 7 has managed to scoot past Windows XP in terms of market share and is now the most popular operating system in the world. Its predecessor, Windows Vista, never had a shot of beating XP.

Windows 7 has been a success for Microsoft, and has salvaged some of the damage done by Vista to the larger Windows brand. Windows 7 has sold some 450 million copies of Windows 7, the company claimed at it recent BUILD event.

By the numbers, Windows 7 now controls some 40.17% of the market, with XP in second place with 38.72%. As you can tell by the chart, this changing of the guard was long in the making:

2011 10 13 1134 520x268 Windows 7 zips past Windows XP to become most used OS in the world

Microsoft has recently been on a campaign to continue Windows 7 momentum, even if that comes at the expense of Windows 8. The company is looking to continue converting enterprise customers over to Windows 7, telling them this week that they should continue their update cycles and not worry about the next version of Windows.

On the face of the issue, this might seem odd, but it must be realized that Windows 8 remains an experiment, and a challenge, while Windows 7 is as vanilla from a ‘Windows perspective’ as can be. This means that if its goal is to get companies off of XP, which has aged, Windows 7 is the obvious choice. Even more, a company could decide to ‘wait and see’ about Windows 8, and then not like it, and remain on XP for several more years. Microsoft, which will eventually phase out support for the old software, wants the to move, and pronto.

And based on the chart above, it is making headway. Windows 7 momentum appears strong, and maintained, while XP and Vista bleed to it. Windows 8 might be the next best thing, but right now we compute in a Windows 7 world.