Ok so ima cut to the chase. So my friend has a prebuilt computer from Gateway (DX4870-UB17) and i have a custom built computer. He was going to buy the computer off of me, but then i would have to erase my entire hard drive and i was thinking if the shortcut to this would to use his HDD, since i don't have to go through the hassle of redownloading the windows AND installing the drivers. I don't know if his HDD still contains the windows and if it does, i then will have the install the drivers still right? Oh and the model for my custom built computer's motherboard is Asus M5A99FX PRO R2.0 ATX AM3+ Motherboard