Problem with using his resotre disk (Captain Obvious to the rescue!) is that it'll be his laptop key in theory. I've no clue how new that laptop is off hand but lately the OEMs have been making a restore partition on the drives and giving you a CD that is basically a boot disk for that partition. Loads up and goes to town on your drive while giving you a nice clean setup. Works great so long as that partition still exists.
Surely all the recovery discs are identical (mass manufatured pressed discs), that ask for the PC's serial number? It shouldn't matter whose restore disc is used.