Windows 10: Reinstalled Windows 10; now key is no longer recognized

I run Windows 10 via virtual machine (Parallels) on Mac. My start menu kept giving me a critical error, and after unsuccessfully trying a number of solutions I found online, I figured my only option was to ditch the instance of Windows and reinstall it from scratch. Unfortunately, the new instance of Windows will not allow me to use the key that I previously used to activate it, because it thinks that key is associated with a different device. How can I inform Windows (or Microsoft) that the old device was a virtual machine that is now destroyed, so I can continue to use the same key?

:)

 

How to reinstall Windows 10 if my computers used the free upgrade from 7 and 8?

Will windows 10 still accept the license keys from 7 and 8 now if I reinstall my computer?

Does Microsoft keep a list of users who upgraded to Win 10 using their 7 and 8 keys so that when users need to reinstall windows 10 the old keys would work?

Do I need to call in Microsoft to ask them to activate my Windows 10 when I give them my win 7 keys?

Both computers are laptops. The windows 7 machine had the serial printed on the back, and I needed to enter that when I upgraded to 10. The windows 8 machine had the serial built in inside its boot system so I didn't need to enter the key when I upgraded to 10, but I did manage to write down the keys using a fetcher program.

 

Tablet no longer recognized

My ASUS tablet is no longer recognized by Windows 10. When I try to reinstall the driver I get a INF file is invalid error. Any suggestions (I reset my tablet to factory conditions, but it still is not recognized).

 

windows 10 key

Thanks but I don't want to do any decrypting. I want to download a Win 10 ISO from Microsoft and install it using my Win 8 key. No other steps required. Is that possible?