not too sure about the tos but it sounds like you may be playing pirated sofware (unauthorized copies). Either that or your disk is damaged. There is a solution for both and are the same thing.
The purchased version could be patched with a no cd crack. Beware some of these cracks are laden with malware so use at your own discretion. search in google for <<NEED FOR SPEED MOST WANTED 2005 No cd crack>> and surf to find your solution.
For all the software companies: keep in mind that this is assuming that he has a legitimate copy of the game and you guys can't mail him a replacement cd for a couple of bucks