Acording to Net Applicatons, Microsoft's Windows XP operating system continues to lose market share but still remains as the top operating system as of April 2012. Windows 7, on the other hand, is catching up to Windows XP and will eventually overtake XP as the most popular operating system.
As of April 2012, Windows XP remains at the top but its market share is falling, while Windows 7's market share is rising. Researchers expect Windows 7 to beat Windows XP in market share by next year. Windows Vista, in case anyone was curious, remains dead in the water.