It's now been exactly two years since Microsoft ceased support for Windows XP, meaning that users of the OS are no longer covered with security updates. As such, vulnerabilities in the software waiting to be exploited – yet still a worrying amount of people are using Microsoft's zombie-like operating system.

How many exactly? According to one bean counting firm, Netmarketshare, as of March Windows XP still holds a 10.9% share of the desktop OS market. More people are currently using XP than Apple's OS X 10.11 El Capitan (4.05%) and Windows 8.1 (9.56%). Windows 10, which saw a big jump to overtake XP in February, is marginally more popular with 14.15% of users; however, neither trouble Windows 7 and its 51.89% share of the user base.

That's a considerable chunk of die-hards using Windows XP, and quite a remarkably large figure for an OS which was launched in 2001. Back in the day, Microsoft spent over a billion dollars marketing XP, but we're guessing that even Redmond didn't think it would be so entrenched that so many users would remain 15 years on.

And all of those users, of course, are exposing themselves to obvious risks.

Key features

Why was Windows XP so popular? The fact is that it introduced a lot of major new features, and it was also a matter of good timing for Microsoft, with the operating system being a major improvement on the poorly thought of Windows ME – with its successor Vista being delayed, and then badly received upon release.

There may be many reasons why people are still clinging to Windows XP, but perhaps the two-year anniversary of support ending will be a useful prompt as to just how out-of-date this OS now is.

If you're still on XP, it would be well worth thinking long and hard about finally making the switch – and if you're not willing to touch more modern versions of Microsoft's desktop OS with a barge pole, then maybe that switch should be to Linux.