Windows 7 has passed the 10-year-old Windows XP in U.S. usage share, according to data from an Irish Web analytics company.

In the first 10 days of April, Windows 7's average daily share was 32.2% as measured by StatCounter, besting XP's average of 30.7%.

It was the first time that Windows 7's U.S. usage share was higher than Windows XP's.

Microsoft has touted Windows 7's sales numerous times since its October 2009 debut, and has repeatedly said the operating system is its fastest-selling ever. Analysts have agreed that Windows 7 has been a success, especially compared to the lukewarm reception customers gave its predecessor, Vista.

Last January, Microsoft announced it had sold over 300 million Windows 7 licenses.

By StatCounter's tracking, other widely used operating systems in the U.S. include Windows Vista, with an April average of 19.5%, and Apple's Mac OS, with 14.8%.

Full story: Computerworld