um ok...
my hardware - Sempron 3400+ 1gig of value ram - geforce 6200 unlocked (w2k not that xp crap)
it plays Doom3 perfectly with high settings and everything maxed.. dont ask me how many fps i never benchmarked - dont care to - it never drops any frames so i dont care
im using slightly older video drivers - i run a minimal system - lots of services shut off not many things running in the background
try reading a bit about cleaning up non essential software
check out all your hardware drivers (as a few others have mentioned)
dig around in Google for a while about non essential windows services
defrag, scandisk
also find out how hot yur whole system is getting - CPU - video card
again as already mentioned, check if your onboard Video is disabled
if you cannot afford a virus scanner *avg free* is better than nothing at all
look into a better firewall - i kinda like zone alarm myself
(just my opinions)
i would be willing to bet if this isnt a heat issue then somethin is dodgey in the software area - your hardware is definately good enough to play yur games without being a slideshow
(fact)
for gods sake dont go overclocking until you know the real issue - if you are already overheating, overclocking is not going to help even a little bit, it can in fact make things worse
Asta 8)