Do a windows complete reainstall. Is the cleanest and most error proof way to do it
If you replace the mother, windows would automatically detect the hadware driver and try to replace them with the correct ones, but you can bet that you would have to reinstall some of them manually. And you can have problems anyway in the future or need a clean install anyway.
You can retrive your windows ultimate serial:
http://
Then you just need to download a ISO of the same version of Windows Ultimate that you have, And use it with your key. Just boot it with RUFUS (
http://) into a USB stick and install