Windows 10 was used by 17.43% of all PCs worldwide in May 2016, according to the latest data from Net Applications. That's a big increase compared to April's 14.35% share for the OS.

Windows 10

The new PC OS market share numbers showed Windows 7 on top with 48.57% in May, a slight drop from 48.79% in April. Windows 10 is in second place, and Windows XP, which Microsoft no longer supports, remains in third place with 10.09% in May. That's actually higher than its 9.66% share in April. Windows 8.1 is in fourth place with 8.77% in May, down from 9.16% in April.

Microsoft recently announced that Windows 10 was in active use by over 300 million devices since it officially launched in late July 2015. The company will release a free Anniversary Update for the OS sometime later this summer with a number of new features and improvements. However, consumers who still have Windows 7 or 8.1 on their PCs have less than two months to take advantage of Microsoft's free upgrade offer to Windows 10. It will end on July 29 and after that date they will have to pay $119 to get a copy of Windows 10 Home.