LordKuruku: For anybody interested in getting Thief: The Dark Project on GamersGate, or anybody who already has but couldn't be bothered to circumvent this, the game is DRM free, but GamersGate, of course, prefers to make things difficult.
Instead of simply changing the launch file to an installer while running, it changes launch into an installer and back for a split second. They want you to rely on their own installer and "call home" for a supposedly DRM free game. The good news is, I've made a handy batch file which makes copying the "setup.exe" file easy.
Just save the attached image as a batch file (rename from "ggcopy.jpg" to "ggcopy.bat") and place it in the folder that contains all the other temporary files. You can do this manually if you're quick, but this method is foolproof. Thief: The Dark Project is fully DRM free if you do this.
I'm a little confused on what your trying to say. I'm also trying to comprehend your batch file. You delete setup.exe from c:\ and then copy the local setup.exe to c:\. So what's the point of the loop exactly if you've already instructed it to copy the new setup file to c:\? That if statement will always be true otherwise you'll get an error said file is missing at the start of the loop when you first go to copy and the program will fail.