please help me. isnt there a download or something because i got it off the clearance rack at the shop and there was only 1 disc.

Welcome to the Forums!

Unfortunately, Myst IV: Revelation installs and plays from a 2-DVD set, and there's no download for the second DVD.

That must be why the game was on the clearance rack. You should be able to return it since it's not complete, even though it was on clearance. The shop ought to be willing to give you your money back, or at least give you store credit.