Maximizing my pc performance

Anyone have any downloads, adjustments, anything really that will improve my computer? I play bf2, hl2 , cs sourse, simcity 4, and it runs fine with it but why not try to improve it. Here is what I have

Pentium (R) 4 CPU 3.06 GHz
3.07 GHz, 768 MB Ram
ATI Radion 9800 Pro

Any suggestions? Thanks

[ShockTroop]

http://www.fixyourwindows.com/optimizewindows.htm

http://www.tweaktown.com/cat/guides/index.html

Be careful when doing some of these things, though (especially the registry), because unless you know what you're doing, there's a chance you might screw up your system.

[Cowpers07]

You can also try some of mentioned in here;
http://www.overclockersclub.com/guid...services_2.php

You can set to manual if you are not sure you believe what the link says, then if the service is needed it is turned on by demand.