I dont know if anyone has mentioned these before but these are probably the 2 best tools I have ever used. They come from Sysinternals and they are free. One is a real time registry monitor and the other is a realtime file monitor. They are aspecially handy if you are going to use some kind of PC tweaker on something that will modify your settings. Say you are going to run Game Gain. Start Regmon, and once Game Gain is finished, Stop the monitoring and then you can scroll through and see every change it made to your registry.