Microsoft's Windows 7: Fastest-Selling Operating System Ever?

Microsoft (MSFT) says it has sold more than 240 million Windows 7 licenses in the past year, making the operating system the fastest growing in history.

Net Applications found that 93% of new personal computers -- and more than 17% of all computers worldwide -- are equipped with Windows 7, Microsoft spokesman Brandon LeBlanc wrote in a blog post Thursday. LeBlanc added that Microsoft products scored higher on consumer-satisfaction surveys than competitor Apple (AAPL).

Microsoft, the world's biggest software company, hopes its entrance into the rapidly expanding tablet-computer market -- currently dominated by Apple's iPad -- will boost Windows 7 sales. Microsoft CEO Steve Ballmer said earlier this month that the company will start selling its so-called "slate" computing devices during the 2010 holiday season.

Analysts are closely watching Microsoft's entry into this market. Goldman Sachs analyst Sarah Friar downgraded Microsoft shares earlier this month, in part because of the company's lack of a tablet product. The company needs to get into the tablet market to fend off threats to its profitable Windows operating system, she said.