The error message is generic and not much help, nor could I find too much on the web. I'm suspecting it has something to do with not being able to tell if the CD is in the drive, even though that's not the error you should be receiving. You don't supply enough additional info to be of much help. The path to your CD must be the same path as when you installed the game, so if for any reason you changed the drive letter, the game won't play.
Only advise I can think of is to do a reinstall and make sure you have the right patches. You don't say if it's Talonsoft or Matrix, but Talonsoft has to be patched.
Jason Petho wrote out an excellent list of installation and patching instructions at the gamesquad site. Go here if you want to check out your install:
http://forums.gamesquad.com/showthread.php?t=20307.
Hope that helps a little and good luck.
Resolve then, that on this very ground, with small flags waving and tinny blasts on tiny trumpets, we shall meet the enemy, and not only may he be ours, he may be us. --Walt Kelly