Ballmer's Legacy: 10 Highlights And Lowlights For Microsoft's CEO

Windows XP

Windows XP had its share of detractors when it was first released in fall 2001, but the operating system has aged like a fine wine and is now seen as arguably the best version of Microsoft's flagship product line. The OS became a blockbuster for Microsoft and a mainstay on corporate PCs across the world. In fact, Microsoft says there are still more than 100 million PCs in North America running XP.