
Windows 7
Windows 7 has passed Windows XP global usage for the first time since its release in October 2009.
Windows 7 now accounts for 40.21% of all global desktop operating system usage across the world. Windows XP usage slipped to 38.64% in the month of October according to StatCounter. The drop in XP usage has been consistent since Windows 7′s launch but October marks the first time that Windows 7 has passed Windows XP usage, an important milestone for Microsoft after two years of Windows 7 sales.
Windows 7 quickly rose to popularity following positive reaction from early beta copies of the operating system. Released in October 2009, the operating system has received praise from consumers, businesses and the media. In November 2009, Windows 7 managed to surpass Apple’s Snow Leopard market share in just two weeks. In early February 2010 it was revealed that Windows 7 had reached 10% market share in just three months. Windows 7 also passed Vista usage in July 2010, just 10 months after its release.
Windows 7 celebrated its first birthday after selling over 240 million licenses in the first year of sales. Gartner believes that 42% of all PCs worldwide will run Windows 7 by the end of the year. The company’s research also indicates that 94% of new PCs will ship with Windows 7 in 2011. By the end of 2011, nearly 635 million new PCs worldwide are expected to be shipped with Windows 7. Microsoft recently revealed that it has shipped over 450 million licences of Windows 7. The figures are a testament to the popularity of Microsoft’s latest operating system. Despite the impressive stats, Microsoft is pushing ahead towards Windows 8. The company unveiled its “reimagined” Windows 8 last month. The new interface features a Start Screen with identical styling to the company’s Windows Phone software. Microsoft is planning to allow application developers to create Metro style apps that interact with the Start Screen and operating system. Microsoft’s unique approach will also provide rich and easy integration across applications for developers. Microsoft is expected to make Windows 8 available on ARM and Intel based tablets in mid-2012.

Top 5 operating systems from Oct 2009 to Oct 2011 - StatCounter