Microsoft Friday celebrated one year of Windows 7 in the market, noting that it’s the fastest selling version of the nearly-ubiquitous operating systems ever, having sold “more than 240 million licenses” worldwide in its first year.

There’s no doubt Microsoft’s got a success on its hands with Win7. A year into its existence, the OS has 17 per cent global market share according to Net Applications, and is on 93 per cent of the new consumer PCs sold worldwide, from 18,000 Microsoft OEM partners. (Those stats are according to Microsoft.)

While 240 million sales worldwide is absolutely nothing to sneeze at, here’s what Microsoft’s solution providers should really be celebrating on this occasion.

First of all, Microsoft’s blog post celebrating the first anniversary of Windows 7 in the marketplace features several of the company’s top Windows team members, Canadian Mark Relph included, giving their top seven (I see what you did there!) favorite things about Windows. It’s mostly a list of favorite features and functionality.

But here’s what the lists are missing, and the biggest reason solution providers should be celebrating this milestone: Windows 7 gave Microsoft its swagger back.

Through the end of the Windows XP era and throughout the Vista era, Microsoft was a company on its heels, and justifiably so. It was hard to find positive user experience for Vista, and businesses stayed away from the operating system in droves. In fact, many who bought new systems with the OS pre-loaded went out of their way to avoid that particular minefield. It got to the point that by the 2009 version of the company’s Worldwide Partner Conference – months before Windows 7 hit the market last October – even the company’s top executives had thrown Vista under the bus in favor of the hope of what was to come.

And that hope turned out to be justified. Reviews of the operating system have come in overwhelmingly positive – and not just in a damning-through-faint-praise “Hey, at least it’s better than Windows Vista!” kind of way. And the company’s partners have reported that many customers were willing to look at moving to 7 very early in its lifespan, both because of the aging feature set of Windows XP and because of the perception that Windows 7 was essentially “Windows Vista done right” encouraged customers who had stayed on the sidelines with Vista.

The success of Windows 7 leaves Microsoft with just one more front on which it has to recover its good name – the mobility market. And if the dramatic partner excitement over Windows Phone 7 that was evident at this year’s WPC in Washington D.C. translates into any type of commensurate success in the marketplace later this year and into this year, the company could well have that feather in its cap in time for WPC 2011 in Los Angeles next summer.

Windows 7 is not a perfect product, and Microsoft is certainly not a perfect company. But at least it has its platform strength back. And if nothing else, that’s a solid reason for Microsoft partners to celebrate the OS’s first birthday.