That 750 Watt PSU likely has "rails" so list what each rail delivers in Amperes and why not try the video card on another rail?
It is still possible this machine is no gamer rig so be prepared for a new motherboard and OS.
First off I have...
ACPIx64 based pc
1 TB harddrive
NVIDIA Geforce GTS 250
running on Windows Vista 64
Made by Hewlett Packard model number: p6140f
processor is a Intel Core 2 Quad CPU Q8200 2.33 GHZ
8 GB of RAM
with a 750 watt power supply
This is the only place I could think of who might have an answer, considering HP's customer support is (to put it bluntly) useless.
Whenever I certain games I'll be able to play intermittently and my comp will then eventually completely shutdown and go into a restart, with no warning or blue screen of death. I say certain games because it doesn't happen always or depend on the game it just happens whenever I play a graphically intense game.
Thinking it might be a heat problem I switched out the factory fan for a Thermaltake CL-P0466 SpinQ Quiet Copper Heatpipe Univrsal CPU Cooler with Blue LED for Intel LGA 775 and AMD AM2. Its the best that I could get that would fit within the constrained space. Granted it works better than the original and my system now runs at 28 degrees Celsius normally. I even open the machine and have a small fan blow into the tower, which seems to help.
But even with all this my computer still "glitches" and completely shuts down into a restart. Are there any thoughts or help that could be offered would be greatly appreciated.
And yes my drivers are completely up to date.
Thakyou for any assistance.