This post is ages old, i found out how to do it but it didnt work, it was still asking for the cd to start the game, maybe i didnt do it right but im sure i did
The "no cd" cracks wont work with this particular game either as it makes it think your using cheats etc so it wont let you play the game(battlefield 2142)
so ive just give up and keep the cd in the drive.