All games crash on me after ~20 minutes

[tonytea]

Hi everyone,
Hope you can help me here. I've recently upgraded parts of my system to the following specs:

AMD XP 3200 CPU
with Arctic Cooling Copper Silent 2 Tc
ATi Radeon 9800 Pro
SoundBlaster Live! Value
MSI K7N2 Delta-L Mobo
2x Crucial 512mb DDR 400MHz PC3200
Western Digital Caviar SE 160GB
Antec True Power 430W ATX Power Supply

And I'm getting a crash in any game I play (From Far Cry to Thief 2) after between 20min-1hour. They just bomb straight out to the desktop. XP itself is fine and stable.
XP was installed onto the new hard drive with latest hardware drivers installed straight onto there. I've updated all gfx/sound/mobo drivers.
I've turned Fast Switching to OFF in ATi control panel which has prolonged slightly the period I can play for, but that may just be wishful thinking.
Temperature-wise I'm getting about 50c idle and up tp 60c when playing games

Are there any obvious checks I can do, gfx/sound card/bios options that are known to cause instability with these bits of hardware?

Any help greatly appreciated.

Tony.

 

[globalcitizen]

This is most likely due to bad memory. Run memtest and see how many errors you get.

 

[tonytea]

Righty-ho. Got memtest now - I'll run it tonight (at work at the mo) and see what results I get.
Cheers.

 

[blindtothagame]

definetly start looking into the memory
if memory is good m/b defected video card

 

[tonytea]

Well I did three passes of memtest and brought up no errors.
Any way of checking the gfx card out other than buying a new one and swapping it (which I don't want to do unless the one I have *is* borked)?