If you are using Origin, double check the location where it is installing the game. Origin changed the default install location with their last patch. All Origin games now install to "Origin Games" on your drive. The trainer is looking for the game files in "Your Drive\Program Files\Electronic Arts\Mass Effect 2". You can create an empty Electronic Arts file, then cut and paste ME2 from the Origin Games into it.
I have managed to get the trainer working with my origin version I had to Repair install then in the Binaries folder I made copies of the original .exe and .par files just in case. Re-name the First MassEffect2 .exe and .par files as MassEffect2(1) and re-name the ME2Game .exe and .par files as MassEffect2 . It worked on my end hope it works for you. Be sure to repair. When I tried to re-name them the first time it came up with an error of a missing .dll file so something might be missing.