To be honest there is no real programs what can do that, all I can say is over-clock your GPU and CPU and possibly your RAM but if you have no experience in over-clocking don't do it.
But yeah all I can says is upgrade you RAM and your GPU and that will increase FPS with some games.
Also to add these specifications arnt really ideal when you are trying to run GTA IV on them, due to the fact the game was crappy imported to PC and the specs what are required are really high and costly.
If you want to play GTA IV I would say invest in a decent gaming PC.
