Getting CTDP 2004 to work is a bit of a joke, really.
RH2004 - download the .exe, run it, play it.
CTDP2004 - download it, install it, crash. Download 'Expansion pack' for the mod you haven't installed, can't unzip it as it's corrupted. Download it again from another site, install it, crash. Install a clean copy of F1C, install both things in the correct order, run it, can't load tracks...
So far, i can do practice sessions and that's about it. Shame really, as the car models are fantastic, tons more detail than the RH2004 ones.