LOS ANGELES, US: Microsoft Corp Chief Executive Steve Ballmer said on Thursday sales of Windows 7 were running at twice the level of any previous version of its operating system.

Windows 7, launched a month ago, has "already sold twice as many units" than any previous version in a comparable time, said Ballmer at the software company's annual meeting in Bellevue, Washington, which was broadcast on the Internet.

Microsoft did not give any details or actual sales figures. Consumers and PC manufacturers have generally welcomed Windows 7 after the disappointing Vista.