Transferring the game “medieval 2 total war” to an

Well i’m trying to save this guys stuff from his HDD. He f-ed up his OS bad (Vista sp1) and well now it doesn’t boot up in anything except safe mode. Basically i’m going to install a new OS (windows 7) and backing up all the important stuff.
Unfortunately he has a game on there called “medieval 2 total war” with 4 expansion packs and he claims that he can only use the cd-key once and won’t be able to re-install the game because he used the key already in the current installation. So how do I back-up his game so it’s playable on another computer/installation?
Or is he mistaken and he can use the key again?
Answer #1
I believe he’s mistaken. The computer (since it’s f’ed up pretty bad) would have no way to record whether the CD key was used previously, as it is usually saved in the registry of the computer (which I believe is wiped upon a format/new OS). Also, as far as i’m aware Medieval 2 total war does not use Securom or internet registration to keep track of what CD keys are used.