Windows XP: the 13-year-old operating system refuses to die.

(Credit: CNET)

Windows XP will not die, according to January numbers from Web tracker Net Applications. But the not so well loved Windows 8.1 is also seeing some life too.

The doomed operating system -- that would be XP, support for which will end on April 8 -- actually gained a fraction of a percentage point of desktop OS share, rising to 29.23 percent in January from 28.98 percent in December, according to Net Applications.

Put another way, about two months before Microsoft pulls the plug, Windows XP still powers more than one-quarter of all PCs.

Microsoft is concerned because the end of support for XP means that PCs "go unprotected," as the company warns on an end-of-life XP page.

In January, Windows 8.1 finally passed Vista. Windows XP made a small gain.

(Credit: Net Applications)

But it's not all bad news for Microsoft. Windows 8.1 finally passed Vista: the former had a 3.95 percent share, up from 3.6 percent in December, while the latter registered 3.3 percent, down from 3.61 percent in December.

But Windows 8/8.1 combined share still pales in comparison to the Windows 7 trajectory, after its release in 2009. After less than one year, Windows 7 had a 17 percent desktop OS share.

After 15 months, Windows 8/8.1 is far below that.

Windows 7 was off slightly in January to 47.49 percent. It recorded a share of 47.52 percent in December.