At the end of last month, Windows 7 had a 14.46% share, while Vista fell to 14.34%, according to NetApplications. When Microsoft released Windows 7 to retail in October 2009, Vista had an 18.83% share.
While Windows 7 sales have been strong, the older XP remained king, accounting for 61.87% of the worldwide usage market at the end of July, or more than double the share of Vista and 7 combined, the firm said.
Windows 7 sales were a major contributor to Microsoft's 48% increase in profits year to year in the fourth fiscal quarter that ended June 30. Revenue in the quarter rose 22% as business increased spending on replacement PCs running the latest OS. Sales of Office 2010, the latest version of Microsoft's productivity suite, were also a key profit driver.
Unlike Vista, which was generally panned by businesses, Windows 7 is seen as offering a number of improvements, including built-in support for touch-screen applications, a lighter footprint and less intrusive security measures than Vista. In March, Microsoft reported selling 90 million copies of Windows since its release, making the software the fastest selling OS in the history of the PC industry.
Nevertheless, interests in XP remain strong. In July, Microsoft said businesses buying PCs with Windows 7 Professional and Ultimate preinstalled would have the right to downgrade to XP throughout the life of Windows 7. The company had previously said that option would expire with the release Windows 7 SP1 last month.
Meanwhile, Apple's Mac OS X remained small player in global usage. As of the end of July Mac OS X 10.6 had a 2.48% share and Mac OS X 10.5 a 1.82% share, according to NetApplications.