If you you goto the start button on windows 7 then look for the launcher, right click it then open file location, whatever your exe is called, rename it to what the trainer needs (make sure your using the right trainer, mine is crusade 2.5) I am using the latest crusade 2.1 trainer on here, it reqs process GC3Crusade.exe so I renamed whatever mine was called before to it .. think it was just crusade... anyway it worked except the research option.
Note::
Make sure you run the .exe, the launcher will look for the original named file, so you cant use it, just errors or dont load. Make a note of the original name (unlike me) so you can rename it for updates etc