anybody able to help me with this? i got the game off of steam, typed in my code (correctly) and it said that my code was taken. the game i have is Trainz 2010 Engineers Edition.
I think you will have to take it up with Steam. It is probable that they sent you a repackaged disk that had been returned for refund. If the previous buyer had registered it it cannot be registered again.
Have you checked your profile? I don't know how the Steam system works but that number could already be in your profile. Worth a check.