I bought a gaming computer that has windows 7 ultimate installed and I want to install a clean windows 7 premium. (one of the two hard drives is messed up, it has the boot program on it.) I'm getting Windows 7 premium system builder OEM version and was wondering if there are any issues with this? I've read that it locks to one motherboard, and I just want to make sure that it's ok to use on a computer that has already had windows 7 installed before. (I'm buying it new from amazon btw)