Haxorx21 :
I have a prebuilt acer pc that has the oem system builder license on it. I got the activation key using the command prompt (admin). I am doing a full upgrade to the pc but reusing the cpu and hdd. Can I deactivate windows on this pc then install the new motherboard and then activate it with the same system builder key? I really do not want to re buy a windows 10 key for over 100$
Assuming your current Win 10 has been upgraded to teh 1607 release, read and do this
before you change any hardware:
http://www.tomshardware.com/forum/id-3164428/windows-build-1607-activation.html
This will link your OS license to your Microsoft account rather than to specific hardware.
Bottom line - you may not have to buy a new OS license
EDIT: Oh, a prebuilt Acer. That above may not work. Sorry.