A screen shot of Windows 7

More than 10 percent of all personal computers worldwide are now running Windows 7, making it by far the fastest-selling operating system in history, Microsoft said.

"Business customers are beginning to refresh their desktops and the momentum of Windows 7 continues to be strong," Kevin Turner, chief operating officer at Microsoft, noted in a statement.

"Windows 7 continues to be a growth engine, but we also saw strong growth in other areas like Bing search, Xbox LIVE and our emerging cloud services," said Peter Klein, the company's chief financial officer.