The OS wars, Vista strikes back at Mac OS X

Windows Vista more than doubled its market share in March, while the share of computers running Mac OS X fell for the first time in nine months. Read on for an overview of the complete stats.

Microsoft said last week that it had sold more than 20 million licenses of Vista, surpassing the 17 million licenses for XP it had sold in its first two months of general release.

Market share per OS

Some analysts have predicted that despite Microsoft's plans to spend half a billion dollars marketing Vista, conversions from XP won't be the norm until 2009.