During his Microsoft Worldwide Partner Conference keynote on Monday, Microsoft CEO Steve Ballmer announced that the company has now sold 400 million Windows 7 licenses to date. Microsoft’s current operating system was first launched in October 2009, and it was welcomed with open arms as customers were eager to dump Vista following its troubled introduction. Despite an impressive 20 months for Windows 7, it is still far from being the world’s most used operating system. Windows XP’s share was near double Windows 7′s in June, though Microsoft did confirm on Monday that it would stop supporting the operating system 1,000 days from now. According to Net Applications, Microsoft’s Windows 7 operating system was used on 27.13% of the world’s personal computing devices as of June 2011. Windows XP still ranked No. 1 with 51.13% and Vista occupied the No. 3 spot with 9.52%.
