Nearly three years after its launch, Windows 7 is poised to replace Windows XP as Microsoft's most popular operating system, a Web analytics company said Sunday.

According to Net Applications, a U.S. firm that tracks browser and operating system use by monitoring the number of unique users who visit the 40,000 websites of its customers, Windows 7 powered 41.6% of the computers that were online during June. Windows 7's share was 1.1 percentage points higher than the month before.

The 11-year-old Windows XP, meanwhile, accounted for 43.6% of all systems, a slide of 1.2 points.

The continuing climb of Windows 7 and the decline of Windows XP means that the former will probably pass the latter sometime this month, Net Applications said.

"Based on trends Windows 7 may surpass Windows XP in usage share [in July]," said Net Applications on its website Sunday.

Computerworld's projections confirm that.

If the pace of change over the last 12 months holds, Windows 7 will finish July with 42.7%, ahead of XP's 41.7%. Using an average of just the last three months -- a period of especially large declines by XP -- Windows 7 will wrap up July with a 42.9% share, while XP will drop to 41.5%.

PC World