well, check the temperatures first. try these things before spending on anything:
<b>1.</b> Check the temperature, if it is below or around 50 at full load, then its okay.
<b>2.</b> Reduce the CPU speed, FSB first, if required the multiplier too. If things improve, you are having problems due to high speed, which happen due to a number of factors - memory not being able to handle this high speed, PS not being able to deliver enough current, CPU getting too hot,
<b>3.</b> Check the nVidia and other drivers, install the latest drivers and their patches if any.
<b>4.</b> check your windows install, you may require to reinstall windows. maybe some drivers have a conflict.
<b>5.</b> Since you already have a 350W PS thats no worry, continuously monitor the voltages on load, you could opt to keep logs of PC Health data that would help you diagnose the problem. The PS might not be delivering enough current on load leading to a dip in voltage. In this case, you would need to increase the volatge a bit, or adjust the current liiting potentiometer in the PS, yoou have to consult its manual or get a technician.
girish
<font color=red>No system is fool-proof. Fools are Ingenious!</font color=red>