Really? I thought that if you changed motherboards, you'd have to get it re-activated... Cuz i swapped HDD's once already (used Norton Ghost for this), and i figured that it just accepted the new HDD, since I didn't switch motherboards. Cuz I thought OEM locked onto your mobo serial number in prebuilt systems (cuz that's what I have). Maybe I won't have to put a new OS on my new build...(although, I most likely would, that way if I ever had to use this one, I could just turn her on).