Microsoft Chief Financial Officer said Windows 7 has sold 90 million licenses since its October 2009 launch.

“We see continuing momentum in Windows 7 to date,” Microsoft CFO Peter Klein said Morgan Stanley Technology, Media, & Telecom Conference in San Francisco this week.

“We’ve now sold 90 million copies, which is just terrific momentum. … Heading into 2010 and 2011, we’re starting to see incredible interest from our enterprise customers to start deployments of Windows 7.

The interest has been very high, and we’re now having conversations with the majority of our enterprise customers who are making plans to deploy Windows 7, Klein added.

Last November, Steve Ballmer said Microsoft has sold twice as many Windows 7 copies in its first month as any other OS in the same time frame.

Meanwhile, in a blog post, the company said: We're humbled and excited that people are responding so positively to Windows 7 - our customers have made it the fastest selling operating system in history.