Copying SuperBike 2001

[SuperBike]

Hello all, I'm having a problem making a backup of my game. Everytime I make a backup of the game and I try to use that backup to play it, I keep getting asked to insert the disk in the CD Rom, even though it is in the drive already. I've already made a copy and removed the old .exe and replaced it with a "fixed" .exe but it keeps happening. Any help would be appreciated.