Microsoft has closed a loophole that allowed users to continue accessing the free upgrade to Windows 10 and Windows 11 from Windows 7 or 8. However, this has resulted in some users finding that their previously upgraded license key has been deactivated.

For example, if a user upgraded from Windows 7 to Windows 11 after taking the free upgrade to Windows 10, then upgraded their graphics card, they may find that their license key is suddenly invalid.

This issue has affected users such as those reported by The Verge, as well as complaints on Reddit and other online platforms.

It is unclear how many users are affected by this problem, but it seems to occur in certain circumstances, potentially even without a hardware upgrade or due to a simple BIOS update.

One user, Daniel Mittelman, had his activation blocked after a hardware upgrade and was told by Microsoft customer support that because his Windows 10 license had been upgraded from Windows 7, they could not continue his license for Windows 10 Pro after the hardware change.

However, Microsoft is aware of these reports and is investigating the issue. Bill Babonas, principal product manager of Windows at Microsoft, stated that customers experiencing technical difficulties should contact customer support.

While it is possible to use Windows without activating the OS, there are limitations such as the inability to customize the operating system and not receiving updates. This can be far from ideal, so it is important for Microsoft to address and resolve these issues promptly.