Microsoft is now blocking Windows 7 and Windows 8 keys from activating a copy of Windows 11. It’s been a loophole that has existed for years, allowing people to upgrade from Windows 7 or 8 to Windows 10 or 11 free of charge.

Microsoft originally announced the changes to block Windows 7 and Windows 8 keys from Windows 11 late last month, but at the time, we saw that keys were still activating, and it wasn’t clear when the block would actually come into force. As of this week, Windows 7 keys are now fully blocked from clean installs of Windows 11, Microsoft confirms to The Verge.

I’ve tested several Windows 7 keys on a clean install of Windows 11 (22H2) today — and while I could use the keys to install the OS, it wouldn’t activate. “We can’t activate Windows on this device because you don’t have a valid digital license or product key,” reads the error message when you now attempt to activate a Windows 7 key on Windows 11.

If you’ve previously upgraded a machine from Windows 7 or Windows 8 to Windows 11 or used one of these older keys, your activation status won’t change. You have a digital license that should continue to work. But if you were hoping to use this loophole in the future, it’s time to buy a legit Windows 11 key instead.