I already knew this could happen but i read from microsoft official statements that you can do clean install after you activate once and that the activation for people who upgraded will use a machine code from the bios to recognize its your pc again and auto activate, which now i can confirm its fake,unless i done something wrong.
The only way to reinstall now if you want to format or something is to install your old win7 or8 activate that then upgrade to 10.
Else you can only do windows 10 resets.
But what if your windows breaks and wont startup anymore for whatever random reason? you can do a boot from USB install, you will need to do a win7/8 install and then reupgrade.
F*** MS they are really stupid man.