Trouble running Warcraft III and The Frozen Throne.

[Sedmire]

I legitimately own both games, but I burn all my stuff because I go to a LOT of LANs, and frankly, I'm sick of anything being stolen. Anyways.
I can run the games off of the original CDs just fine, which is...cool, I guess. But I can't run either game, on any version, either expanded or not, off of a burn, or a CD image.
I can install off of the images and burns just fine, but when I try to start the game off of either, it asks for me to insert the CD. I click retry a bunch of times, and no dice.
Wondering how I might fix this....