Windows 8 gained 0.83 points of share over the month of June, according to the newest figures from NetMarketShare. That was enough to boost Microsoft's latest OS to a 5.1 percent share of the worldwide PC market, moving it ahead of Windows Vista, which fell 0.48 percent over the same period to a 4.62 percent share.
Windows 7, which surpassed Windows XP's install base in 2011, also dropped 0.48 points in June, ending the month with a 44.37 percent share. Even 12 years after its release, 37.17 percent of computers are running Windows XP.
At just over five percent of the market, Windows 8 has a greater share than any individual version of Mac OS X. The whole OS X install base, though, beats out Microsoft's struggling new OS by two percentage points, 7.2 percent to 5.1 percent.
Total web usage of Apple's OS X passed Windows Vista in September of last year.
Microsoft intended for the latest version of its operating system to reverse a trend that has seen consumers opting for smartphones and tablets instead of traditional PC form factors. Windows 8 was also meant to give Microsoft and its manufacturing partners a foothold in a mobile device segment dominated by Apple on the tablet end.
To that end, Microsoft sank hundreds of millions of dollars into the marketing for the launch of Windows 8, showing off the touch-centric interface along with a range of new hardware form factors blending mobile devices and traditional computers. The software giant touted strong pre-sales ahead of Windows 8's launch, and earlier this year Microsoft noted that it had sold 100 million licenses to date.
Those sales, though, appear to have been largely to manufacturers and not necessarily through to actual customers. The PC market has continued to struggle since Windows 8's launch, with some manufacturers going so far as to blame Microsoft's markedly different interface for driving away consumers.
The Redmond software giant has since sought to breathe new life into its struggling OS. In a considerable reversal, Microsoft recently showed off Windows 8.1, an update to the OS that brings back some features users requested. The new version will even give users the option to bypass Microsoft's "modern UI" entirely, booting directly to the desktop that so many grew accustomed to.