The activation algorithm for Windows XP has been cracked, so those stuck not being able to get the ancient operating system working can now do so – and yes, there are folks who still use this OS.

Granted, it’s a seriously slim – vanishingly so – niche of Windows users, and we’ll come back to that. For most of us, though, this is just a curiosity.

As The Register reports, the encryption algorithm for Windows XP product activation has been cracked and reimplemented, with the details provided via a tinyapps blog post.

This means anyone can now generate a valid product key to install and activate Windows XP offline.

Microsoft turned off the servers required to activate Windows XP long ago, so you can’t use a genuine old product key to activate the OS. Well, not online anyway, though from what we can see on Reddit, Microsoft still facilitated a product activation on the phone back in 2020 – and The Register reckons this way still works.

Analysis: Desperate times, desperate measures…

So, if you don’t want to get on the phone and try to persuade Microsoft to activate your Windows XP when you have a genuine product key that can’t be validated online anymore, you can simply do-it-yourself at home (or in the office) with no fuss.

Why would you ever want to use Windows XP, though? Yes, it was a much-loved operating system without a doubt, for many reasons – mainly that it was such a big step forward for performance, and the quality of the interface, over its predecessor – but it’s obviously ridiculously outdated at this point in time.

However, some people must remain on Windows XP due to legacy software or hardware that won’t work with any more modern Microsoft operating system. These are most likely businesses, who might, say, have eye-wateringly expensive machines that only work with software that runs on XP and hasn’t been updated in forever.

In those cases, this crack could prove very useful, but clearly, anyone running Windows XP is exposing themselves to a whole lot of potential pain in terms of the vulnerabilities present in the OS. Which is why if you are in this boat, whatever you do, keep that Windows XP installation offline for obvious reasons.

Are you now wondering how many Windows XP users are still out there? According to the latest from analytics firm Statcounter, XP amounts to a 0.35% userbase out of all Windows versions (not all that far behind Windows 8, Microsoft’s most recently defunct OS which is on 1.28% as of April 2023).

Cracking rusty old Microsoft operating systems appears to be quite the trend at the moment. You may recall that Windows 95’s (relatively flimsy) activation was recently hacked, with a twist – ChatGPT was fooled into generating keys that worked with the OS (in a small number of cases).