I bought two refurbished (?) HP SFF computers from Amazon. They were older computers fitted with Win10 Pro. I have been pleased with my purchases.
I developed a problem with one of the computers that I could not correct. A system restore would have corrected the problem, but I could never get a successful system restore. I decided to reinstall Win10 but I did not have an installation disk.
I went to the MS site and downloaded an ISO image of Win10. Using Rufus set to MBR, I burned a bootable copy of Win10 to both a thumb drive and an SD card. They both work well as installation media.
I reinstalled Win10 using the SD card over a year ago, bypassing the request for a CD key. During that year, I have never been asked to produce a CD key. Now, when I boot the computer, I get this message:
The key that you are using is either not entitled for this PC or has been modified. Please recreate the key and use it for the designated PC. (By the way, this is a Dell message. Why would it appear on an HP PC?)
The only key I have is the one that came with the computer It is the one I paid for when buying the computer. Apparently, this key was satisfactory to MS for the 8 months I owned the computer before doing a reinstall and for a year after doing the reinstall.
I have no other key and have no idea how to comply with the request of MS. What should I do?