People who still want to get Windows 10 for free can take advantage of a loophole that allows users to get the OS if they already have a valid product key for Windows 7 or 8.1.

Windows 10

Officially, Microsoft's free one-year offer to let Windows 7 or 8.1 PCs get a free Windows 10 upgrade expired on July 29. However, ZDNet reports that many users have installed the OS simply by providing their older keys for Windows 7 or 8.1.

The report states:

Users have been able to both kick off and activate Windows 10 on machines where they've previously installed Windows 10, as well as on machines where they've never installed Windows 10 using their Windows 7/8.X product keys.

ZDNet's Mary Jo Foley got a statement from Microsoft on this loophole:

"Users upgrading their PC for the first time will need to enter a Windows 10 product key. Users who've previously installed Windows 10 on their PC should activate successfully with a digital entitlement when reinstalling Windows 10 on that PC."

So far, there's no word on when, or even if, Microsoft will close this loophole.

Meanwhile, it appears that Microsoft's other free Windows 10 offer, which is only supposed to be for people who use assistive technologies on their PC, could also be a while to get around the expired offer. The download client does not check to see if your older PC uses that kind of software. We asked Microsoft about this and got this statement from a spokesperson:

As we shared earlier, we've extended the free upgrade offer for those who use assistive technology as we continue to make accessibility improvements to Windows 10, including many coming in the Anniversary Update, which is available after the free upgrade offer ends. You may see the Microsoft Accessibility blog here for more details.

We are not restricting the free upgrade offer to specific assistive technologies. If you use assistive technology on Windows, you are eligible for the free upgrade offer. That said, it is not intended to be a workaround for people who don't use assistive technology and who missed the deadline for the free offer.

In other words, while Microsoft isn't checking to see if this offer is in fact being used by the right audience, they also don't want it used by everyone else who still wants to upgrade. There's no word yet on when Microsoft might end this offer.

The bottom line is that there are still ways to get the Windows 10 upgrade for free, but they could end at any time. So if you hesitated to join in before the official offer expired, you might not have much time before these avenues are also closed off.