I'm just making sure there is no error with what I just bought, mainly because this is my first time ever building a PC, and there are so many questions, but anyways I just got windows 8.1 haven't installed it yet or anything just wanted to check if it came with everything, but does a Windows 8.1 OEM come with a activation code or is it built into the disc? I bought this one specifically if it helps you out at all http://www.ncixus.com/products/?sku=91219&vpn=WN7-00615&manufacture=Microsoft&promoid=1413