StarCraft - no luck

[JLrep]

I had StarCraft for a while, and eventually the discs got pretty scratched up so I duplicated them and lost track of the originals. The problem is, at that time I only had a Mac, and when you copy a CD on a Mac it only copies the Mac files (so the disc was unreadable by a PC). Anyway, I recently got a PC and I wanted to play SC on it, so, like the sleazy haxxor-type I am, I simply found a bittorrent file that contained ISOs of both discs. When mounted (either by Daemon or by burning the ISOs to physical discs and insterting those), they started the installation navigator perfectly, but no matter what I do, when I try to actually *play* the game it tells me it had trouble reading a file and to make sure the CD was in (this is not the same error I get as if I try to start the game with no CD mounted).

I've searched online, and the game is referred to as having no copy-protection and being very easy to start up. Is it likely that I'm having trouble with actual copy-protection, bad ISO files, or something else?