This is just a question for future references. Because I have Windows 7 OEM, it's obviously locked to the MB. If I were to ever buy a new motherboard, would it be as simple as buying another Windows 7, and when the computer starts up, I'll just activate? Or will it take more, like a new install?
It would take a new install. If your board goes out and you get a different replacement people have got permission from MS to reactivate the OEM.