For some odd reasons, Windows 10 would not activate after upgrading from Windows 8.1. I called Microsoft and they told me to reinstall Windows 8, then upgrade to Windows 8.1 and upgrade to Windows 10. Microsoft also advised me to call HP and request Windows 8 Product Key should the process failed.
Seriously?
Apparently the “factory-installed” product key caused the error. The end user product key is said to be installed in the UEFI BIOS, encrypted.
I guess I’d have to spend a few more days on this project.