What exactly is wrong with your machine, if you can try and explain then we will get you sorted quicker.
The optimisation steps are on the Mach Download page, you will find it from the downloads tab at the top of the forum. Before you do that run the DriverTest and see what the graph looks like, if it has lots of large spikes then optimisation will help, if its smooth then you shouldnt need to do the optimisation.
Hood