hi. i currently have a windows 8 pro key (i bought it) and my windows is activated. is it possible to change the serial from this key to a media center pro key? so that way i can save my purchased 8 pro key for a desktop computer i'm going to build? edit: i just checked my system properties page and the current installed key is the media center key. does this mean that i can use my purchased windows 8 pro key on a separate computer?