you will need a key unless its slipstreamed into that copy of windows.
youll burn the image to a cd then load it like a normal copy of windows 7, but it wont prompt you for a key.
i pay 77$ a month for my t-mobile account. im by myself, and ive got 450 anytime munites, free nights/weekends, unlimited date(includes internet and texting). i use the HTC G1 from google. wouldnt give it up for the world.