You can still upgrade to Windows 10 using an old Windows 7 and 8 product key

Windows 10

As we're all doubtless aware, Microsoft's freebie upgrade to Windows 10 offer officially expired at the end of last month – but apparently Windows 7/8.1 users can still use their product keys to successfully install Redmond's newest OS.

We knew it was the case that if you had used your Windows 7/8.1 product key to install and upgrade to Windows 10 on your PC in the past, and then thought better of it and reverted, you could still use that key going forward to reinstall and activate Windows 10 on that machine.

But apparently, you can use any old Windows 7/8.1 key – regardless of whether it's had any truck with a Windows 10 upgrade in the past – to install the newest OS, as ZDNet reports.

Indeed multiple sources have said this is the case, so essentially anyone can still upgrade using their old product key.

Breathing room

Microsoft isn't officially admitting that this is the case, but by all accounts, the company may simply be giving a little leeway to those who have suddenly thought better of their decision not to make the move to Windows 10.

After all, this all adds to the user base numbers for Microsoft. However, it's likely that this avenue of upgrading will be closed off in the near future – probably the very near future. Because on the other hand, Microsoft is missing out on cold, hard cash which folks should now be paying for Windows 10.

As we noted earlier this week, there is another method by which you can still get a free upgrade to Windows 10 – although it's certainly a morally questionable one in which anyone can make use of an offer meant for those needing assistive technologies on their PC.

Darren is a freelancer writing news and features for TechRadar (and occasionally T3) across a broad range of computing topics including CPUs, GPUs, various other hardware, VPNs, antivirus and more. He has written about tech for the best part of three decades, and writes books in his spare time (his debut novel - 'I Know What You Did Last Supper' - was published by Hachette UK in 2013).