My Windows 10 got corrupted and I couldn't find any way to fix it. Even doing "reset this pc" from "recovery", while keeping the old settings didn't fix it. The only thing that worked was doing "reset this pc" with "remove everything". Now Windows finally works, but the activation is gone. There is no activation key. I got Windows 10 from a free upgarade from an older version and had an activation key, but now it's gone. I didn't change anything in the hardware. I have a backup of all the files from the old Windows before the reset. I don't have the key from the old version of Windows.
Any ideas?
Any ideas?