So I upgraded from Windows 8.1 to Windows 10. The 8.1 copy is legit. It's an OEM DM license. Which means I have a separate OEM key and product key is not embedded in BIOS. So If I change Motherboard and lose my windows 10 activation, is there a way to get it back maybe by calling Microsoft helpline? OR my windows 10 license is gone forever and I will have to revert to Win 8.1?