sounds like a Power Supply problem.. what is your power supply make sure that the fan is working or that its wattage is high enough? i one had the same problem and it was the PSU ... the fan had stoppped.
what games are you trying to play ?
There is so many things it could be with your short description that its all just a guessing game.
You need to do some trouble shooting of the system, then tell us what you have discovered, so we have a more detailed description of the problem.
Reseat the cooler on your VGA card. That card shouldn't produce that much heat at idle.
Try playing a game for 10 or so minutes, or right before you think it will freeze, and check the temperature. If it is over 70 degrees after ten minutes or so, then your problem probably lies in an incorrectly seated heatsink.
sounds like a Power Supply problem.. what is your power supply make sure that the fan is working or that its wattage is high enough? i one had the same problem and it was the PSU ... the fan had stoppped.
what games are you trying to play ?
In my experiance when your PSU isnt strong enough or failing you will get random resets, instead of freezes.
I would imagine it has to do with heat instead, something is overheating, wether it be the chipset on his motherboard, the CPU, or the GPU, either way it doesnt seem like it is his PSU at this point, but the man hasnt offered enough information at this point to make a intelligent diagnosis about anything.
true but when i had my PSU probablem it would only FU#K up on NFS MOST WANTED and CS:S but other whise the pc would be working perfectly fine so just check it out ... it never hurts
the other parts:
CpU: Intel Pentium 4 3.4Ghz
Cooler: AeroCool HT-102
Memory: Kingston 1Gb DDR2 PC4200
HDD: Maxtor 120GB ATA133 7200rpm
Western Digital 120GB SATA I 7200rpm
Themperatures when just started up
CPU: 46°C
VGA: 46°C
Memory: 36°C
Powersupply: 23°C
HDD: Maxtor 58°C
WD: 47°C
Themperatures after 10 minutes playing FEAR
CPU: 53°C
VGA: 50°C
Memory: 36°C
Powersupply: 27°C
HDD: Maxtor 59°C
WD: 47°C
3Dmark06 score: 690
SM2.0 Score: 326
CPU score: 992
If the card (GPU or RAM, any one of them) is overheating, you'll see artefacts long before it crashes. If its the PSU the system will either turn off (so you have to press the reset or power switch manually) or it will reset/restart/reboot whatever you call it. It won't freeze (means display will go blank).
When it freezes its usually the problem is with drivers. In this case try using different (even OLDER) drivers, especially the chipset patch. The most common symptom is that dosplay freezes but if you don't reset the audio keeps going on, then sometimes distorts, then the audio cntrlr is also freezed. I know b/c this happens to me (nF3 250Gb and Radeon 9600 vanilla), IMHO its b/c the chipset driver and the ATI one are not optimized for each other so there's an infinite loop error (that triggers not in games but when I'm using MSIE AND WMP10). So I've switched to FF1.5.
The problem persists with nForce drivers 5.11 and Catalyst 6.4 through 6.8 (I haven't yet installed the today's release 6.9). I swapped it w/ an AOpen FX 5200 from my friend KM400 build and voila, both ystems worked perfectly. So this narrows sown to driver incompatibility.
I think you're encountering the same. Try swapping ccards w/ someone.