On the verge of Windows 10's release, its predecessor has quietly moved into the #2 spot for market share among operating systems. Windows 8.1 has now overtaken Windows XP, the one time king of all operating systems, but it's something of a hollow victory as Windows 7 still leads by a wide margin.

According to Netmarketshare, as of June 2015, Windows 8.1's usage has increased to 13.12% among all operating systems, while XP sits at 11.98% and Windows 7 still accounts for a dominant 60.98% share. These three OS' also represent the only three with double digit market share.

The numbers are especially interesting since it means that over the year that Windows 7 and 8.1 users will be eligible for a free upgrade to Windows 10, after it becomes available at the end of the month, things could change rather quickly. Certainly August's numbers will look very different. Windows 10 is actually currently on the list with .16% share, due to the people who are part of the Windows Insider program who are currently testing the new OS.

Don't expect Windows 7's monster share to disappear too quickly however. Many of its users will be businesses who won't consider the upgrade to Windows 10 until they know it will work well with the rest of their systems and won't cause them any problems. Still, it will be interesting to watch these numbers evolve over the next couple of months as Windows 10 certainly has the potential to own the operating system market for a very long time.