Microsoft Corp.'s chief executive Steve Ballmer told shareholders at the company's annual meeting this week that unit sales of Windows 7 have more than doubled that of any previous operating system the vendor has released in a similar time period.

The company launched its Windows 7 operating system on October 22^nd.

"Since launch, we've already sold twice as many units of Windows 7 than any other operating system we've ever launched in a comparable time," Ballmer said.

Ballmer offered that the quality of the Windows 7 operating system was driving sales.

"Windows 7 is simply the best PC operating system we have ever built," he said. "It enables people to do more of what they want to do more easily and more quickly, and customers are responding."

The surge in Windows 7 sales can be traced partially to pent-up demand from PC makers such as Dell Computer Inc.

"The launch of Windows 7 is being very well received by SMBs and consumers and we'll see the benefits of that more fully in our fiscal Q4," said Michael Dell, Dell Computer chairman and chief executive.