I am using Windows Vista Ultimate and DirectX10, I don't believe a trainer is available for the most recent patch of Hellgate: London, which is: 1.37.25.4015
I tried it running it before starting the game and when I used the launcher, the application crashed. Have you tested this with this system configuration?
Uh, most recent Single-Player version is Patch 0.1 (1.43.25.4015)