Microsoft had sold 60 million Windows Vista licenses as of the end of June, including 20 million copies sold since mid-May, the company said on Thursday.
The world's largest software maker disclosed the new sales figures on Vista, the latest version of its Windows operating system released on January 30, at its annual meeting with financial analysts.
Microsoft Chief Executive Steve Ballmer took the stage at the company's headquarters in Redmond, Washington with a message that the software maker can still deliver growth by expanding its core desktop and server software business while succeeding in new areas like Web services.
Windows Vista is at the core of Ballmer's vision. New versions of Office and Windows are yielding higher-than-expected renewal of multi-year agreements with large organizations, Ballmer said.
The cash generated from those products, which account for almost all of the company's profit, support Microsoft's newer initiatives like online advertising, its Zune music player, software for mobile phones and online service.
The last Vista sales update from Microsoft was in mid-May, when the company said the new operating system had sold nearly 40 million licenses in its first 100 days.