.MDF! Game installs but won't play!

Ok, so after fiddling around with the .mdf files and finding a program that wasnt blacklisted, i managed to install the game (Fable - Lionhead Studios). bt wen i tried to play it, it came up with an error messge dat sed “ERROR: Cannot find library." And then it closes. Does anyone have any suggestions? Ive got two file types for each disk, .MDF and .MDS. The mds one is really small. Alcohol and daemon tools say that it is an invalid image file, but WinISO opens and extracts it properly. I have no idea what to do! plz help!