Have you tried phone activation after an upgrade? If the qualifying OS was retail it should be possible to reactivate on a new system/hardware. I would suggest attempting phone activation before taking any other extreme measures.
with 7/8/8.1 just need to call Microsoft and tell them what happen, for win10 I think it is the same. the problem is every time I call Microsoft to deal with the activation need about 30~1hrs for discus the problem over the phone, provide info etc, so end up I mod my bios or use kms.
I'm just going by what M$ states in the EULA. Windows 10's license is good for the life of the pc which is the motherboard. If the board dies, then the license dies with it, If it gets zapped by a lightning strike, I personally do not see M$ feeling sorry for you and letting you have a free oem license for 10 If it was a retail license, then there should be no problem getting Windows 10 to activate on another motherboard, not very many peeps have reatil license when you can get an oem version for free OP makes no mention of having a retail disk w/key
I had a similar problem with hardware last week. My Gigabyte motherboard died. I had a windows 8.1 retail upgraded to Win 10. As it was 5 years old, I made a brand new config with Z170 mobo and CPU latest generation. With some utility I wiped my SSD to avoid drivers conflicts with new hardware. I installed Windows 10 10240 ISO from USB, skipped product key and logged with my previous MS account. So what ? Windows was activated at last reboot and I had some previous configs and the personal Wallpaper back. So, I don't understand why some people stay activated on fresh install, and other not after all hardware change. I just keep my SSD and Hard Disk.