Everyone knows that Windows is installed on the vast majority of computers, but it's always interesting to be reminded of what a cash cow the OS has been for Redmond. According to Gartner, Microsoft owned 78.6 percent of the global market for desktop operating systems at the end of 2010 -- up almost 9 percent from 2009. That means, of the $30.4 billion in revenue that various companies generated, $23.8 billion lined Microsoft's coffers. But while Windows remains the kingpin, Mac OS X and -- wai
