Microsoft’s Unsung Success Windows 7 is a smash hit.

Windows 7, the latest version of Microsoft's operating system, is the hottest-selling product in the company's 35-year history. In five months Microsoft has sold 90 million copies. That's twice the rate of Microsoft's last operating system, Windows Vista. "Windows 7 is on a tear right now," says Brad Brooks, vice president of Windows consumer marketing. "The consumer PC segment has exploded since Windows 7 shipped." The growth rate for the consumer PC segment is now 20 percent, versus 6 percent before Windows 7 shipped—likely because a lot of customers were sitting on the sidelines, waiting for Windows 7 before they bought a new PC.