No, you cannot use an 8.1 product key for Windows 10 upgrades.
No, you cannot use an 8.1 product key for Windows 10 upgrades.
I learned that my current Windows 8.1 version won’t get security updates anymore, so I considered switching to Windows 10. After checking, I discovered Microsoft stopped offering free upgrades long ago. Someone on a forum suggested reaching out politely for possible assistance. Eventually, a Microsoft support representative confirmed I could upgrade using my existing 8.1 key, though the installation didn’t complete. If I decide to download the update anyway, can I revert back to Windows 8.1 if the key issue persists?
Yes, the key should function properly, including Windows 7 keys. It seems you might be confused about why you'd need it, but it should work as expected.
Uncertain about the result, but I've tried Windows 7 keys without issues. Verify you're using the exact same edition (e.g., Home=Home, Pro=Pro) as your 8.1 version.
You can retain your files by opting for the upgrade feature rather than a clean installation; however, I favor the clean option. It’s wise to back up any crucial data in either case, as this is standard advice. As for the process, you won’t be able to revert directly to your original, fully intact OS once the install starts—though you can reinstall it afterward. Always ensure your data is saved.