Windows XP is still the dominant OS worldwide after more than 10 years, but Windows 7 continues to narrow the gap.
XP ended last year with a 46 percent slice of the OS market, according to December data from NetApplications. Although impressive after a decade, that number proved a hefty drop in use for XP, which kicked off 2011 with a 55 percent share and has fallen each month since then.
On the upswing, Windows 7 rang out the year with almost 37 percent of the market, a solid gain from 22 percent last January and further proof of its ongoing monthly growth.
In third place was Windows Vista, which dropped to 8 percent from more than 11 percent at the start of 2011.
Microsoft has been on a tear lately trying to convince companies and consumers alike to make the leap to Windows 7.
The company has stressed that support for Windows XP will end in April 2014, making sure to give IT departments enough time to migrate their users to the latest version of Windows.
Microsoft has even gone so far as to advise enterprises still on XP not to wait for Windows 8 and instead plan the switch to Windows 7 now.
Meanwhile, over in the land of Apple, Mac OS X grabbed almost 6 percent of the operating system market last month. OS X 10.6 Snow Leopard was the leading flavor with a 3 percent share, though it has gradually fallen in usage. Ending the year with a 2 percent share, OS X 10.7 Lion has risen in popularity since its release last summer.
And still carving out a niche among its faithful users, Linux accounted for almost 1.5 percent of the OS market in December.