I have 768RAM, ( one 512 and a 256...133SDD), and a 1gb AMD Athlon, and a K7VZA motherboard... Just a note to say that my pc also has problems 'similar' to yours. I have a Nvidia Geforce2 64mb Graphics card with which I play Unreal Tournament a fair bit, ( I'm still crap, but have noticed a considerable improvement lol ). The game will randomly freeze, at any given time during gameplay, (notably just after excessive fights), sounds do a rapid 'needle-stuck-in-the-groove' thing. The computer has to be turned off at the tower, which, like most of you, PISSES me off, it is screwing up my data and important applications. There are some in-depth things you can do in Unreal Tournament to aid the memory of the graphics card, but it is quite complicated, ( I'm not as technically minded as most of you guys ).
Any idiot-proof suggestions would be welcomed. Thanks guys. Email me if you can, or would like to help: remoman1974@hotmail.com

yo i had a 512 and 256 chip in my comp (AMD) and it froze alot, not only in games but while doing anything
as for UT i also play it, and i have a Geforce 2 MX 64MB card, you are using D3D right? ( direct 3D ) there is also a thing you can download for UT to use OpenGL
but anyway i never had it freez on me, does it do it any other times besides in UT?

sounds like a power problem

try unplugging any case fans from your motherboard

and plug them into ide leads as this will give your motherboard more power

uhh.... rob, do you know what ide is? its not th power cables. you really mean plug the fans into the wires from the power supply.

however, that won't correct a power shortage. only a bigger power supply can

i meant the ide power leads and it will help

as power supplys are split into two channels 1 ide (power Lead) 1 motherboard

so there is more power for the motherboard

i have the same problem many times, only it seems to get gradually worse. it used to be only Aliens vs. Predator 2 and No one lives forever that froze up. but now max payne (which used to be VERY stable) crashes all the time with the same repeating sound and i have to turn off the power at the tower..i also am not too much of a tech and i'm very frustrated.
system spec:
Dual AMD athlon processers
Tyan Tiger MP S2460
GeForce3 64MB Exaclibur
Soundblaster Live card
1 gig of RAM