I just bought this game over steam and when I try to run this mod it tells me I need to insert the CD. Obviously since I don't have a CD this is impossible Any help, because it would make going back worthwhile.
The All Ghosts Mod, once installed, should (normally) run without CD. I assume you've bought the UK version. Did you select that version during the All Ghosts Mod installation (and not, accidentally, the US)?