The program does not install anything external, it only adjust your PC settings, so the game can run properly.
Obviously, it does not do any miracles, and if you have an old PC, maybe the game will not run even using GameGain.
Once you have established the parameters, you only have to press go. If you do not like the results, you only have to go back to the previous configuration.
The demo version has a time-limit of 60 minutes per session