Microsoft has sold 90 million copies of Windows 7 to date, making it the fastest-selling operating system in history, according to Peter Klein, Microsoft’s chief financial officer. Klein made the comments earlier this week while speaking at the Morgan Stanley Technology, Media, and Telecom Conference. While most of what Klein had to say dealt with the Microsoft’s financial expectations, the company’s top number cruncher did discuss a few interesting things about Microsoft’s product outlook for the coming year.

Microsoft has sold 90 million copies of Windows 7 to date, making it the fastest-selling operating system in history, according to Peter Klein, Microsoft’s chief financial officer. Klein made the comments earlier this week while speaking at the Morgan Stanley Technology, Media, and Telecom Conference……

It has been only a year since the first beta release of Windows 7 and only 2 months since its public release to retail channels in selected countries throughout the world but it is already clear, says Microsoft, that Windows 7 is the fastest selling operating system in Windows history. The first week stats of the Windows 7 launch week already showed that Windows 7 was outselling Windows Vista at its time of release by 234%.

But it is not only the first few days that Windows 7 performed well in sales. A year over year PC unit sale increase of over 50% in each of the last four weeks of December is another example of the sales figures of Windows 7. Brandon LeBlanc does not deliver hard values which makes the claim that Windows 7 is the fastest ever selling operating system unreliable but still plausible.

If you take the OS Statistics over at W3C as an indicator then you notice the following in the last year: Windows 7 managed to climb to a market share of 6.7% in November 2009. Windows Vista went up one percent from 16.5% in January 2009 to 17.5% in November 2009 and Windows XP dropped from 69.8% in January to 62.2% in November.The figures seem to suggest that most users who have bought Windows 7 have switched from Windows XP and not Windows Vista. It is likely that the trend will continue with Windows 7 climbing the market share ladder quickly.