Microsoft's (MSFT) latest operating system, Windows 8, had 3.2% of global market share in March, according to Net Applications. Earlier-generation Windows 7 topped with 44.7%, followed by Windows XP with 38.7%. Even much-maligned Vista still had 5%. Windows 8 debuted in Oct., but users and PC makers haven't fully embraced features, including touch-screen controls. Overall Microsoft had 91.9% of the desktop OS market, followed by Apple (AAPL) at 6.9% and Linux at 1.2%. Microsoft shares rose a penny.