The fastest selling operating system in history has given sufficient fuel to Microsoft to outpace Apple in terms of consumer satisfaction. Essentially, Windows 7 has beaten Mac OS X Snow Leopard for the boost in satisfaction delivered to end users, revealed London-based market-research firm YouGov Plc. Both on the day of the release of the latest iterations of Windows and Mac OS X, and also throughout 2009, the proprietary OS from the Redmond-based company beat Cupertino’s favorite cat, as data extracted from the respondents in YouGov’s Chart of the Day reveals, according to Bloomberg.

Windows 7, which hit the shelves on October 22, 2009, boosted the level of consumer satisfaction for the software giant to on less than 67% for the entire week after launch. The increase was substantial, no less than 3% in a single day. Certainly, it was more substantial than the jump that Mac OS X Snow Leopard delivered to Apple, just 1%, bumping the consumer satisfaction level to 65%.

At the same time, Windows 7 managed to keep its momentum throughout the end of 2009. No less than 73% of respondents declared that they were satisfied with Microsoft on December 31, namely a 14% growth. By comparison, Apple customer satisfaction only grew by 6.9% by the end of the past year.

Having sold over 60 million copies since release, Windows 7 continues to receive rave reviews and accolades, while Mac OS X Snow Leopard was plagued by a variety of issues. Specifically, Windows 7 was nothing like Windows Vista, while Snow Leopard managed to earn the label Apple’s Vista.

According to Microsoft, the level of satisfaction for Windows 7 is well above 73%. At the 2010 Consumer Electronics Show in Las Vegas, Microsoft Chief Executive Officer Steve Ballmer noted, “Today I think I certainly am very proud to be able to say that Windows 7 is by far the fastest selling operating system in history. But for me, the most important measure of success is what our customers think, and customer reaction with their experience has been very, very good. A recent survey found a 94 percent satisfaction rate among early adopters of Windows 7. All of this is driving great results for our industry.”