Hi my pc has a problem wich it had when i built it a few months back it randomly restarts i have had alot of help trying to solve this problem from another member on the forum (jam) but nothing has worked and im running out of ideas heres a list of things ive tried. 1)changing psu 2)swapping ram 3) xfx found no problems with my graphics card 4) ive tried windows xp but it still restarted 5)borrowed another cpu 6)made sure everything is cooled proper i have an antec 900 that has 4 fans so they should keep the inside cool 7)cleaned registry with glary utilities 8)swapped hdd 9)also tried reinstlling vista numerouse times and installed all the latest drivers. 10) checking the voltage in bios and changing some settings 11) checking the cpu and gpu and ram temp but the temperatures are fine but none of the above has worked although when i tried running ubuntu off disc instead of hdd it ran for 6 hours with out so much as a crash but i swapped the hdd and it made no difference. also the restarts are more frequent now restarting when i open a program or even during boot up but when i install vista it seems to restart at a certain point at the end of the installation but once restarted continues as normal. im really not sure what to try next any help would be appreciated thank you. heres my specs. mainboard: gigabyte n650sli-ds4l op system: vista home premium 32bit psu: corsair tx750w graphics card: xfx 8800 gts 512mb g92 ram:corsair xms 2gb cpu:core 2 quad q6600 2.4ghz case:antec 900 cpu fan: asus arctic square also i have not tried to overclock anything.

ok, this may seem simple but is confused me for weeks. Depending on your processor, it may have a bracket under the mobo to thod the cooling device. IF it does double check no metal is touching any solider joint on the board. Mine had foam, but one solider joint was high enough to touch the metal backing. If there is any touching re seat the backing or request a replacement backing. Also check that your mobo is high enough that nothing is grounding out on the case. If this id happening get slightly taller mobo mount screws. Also a small piece of rubber can keep any pieces from grounding out. you have tried everything but the mobo so i'm guessing it is a grounding issue. Also, you do have the 4,6 or 8 pin power connector connected as well to the mobo right? there should be 2 wired going ot the mobo from the PSU Ultra Gladiator Blk Mid-Tower w/500w V-Series Intel DP35DPM Socket 775 Motherboard Intel Quad Core Kentsfield 2.4Ghz Q6600 CPU Ultra 2048MB PC6400 DDR2 800MHz Dual Channel 2X1024 GeCub

I have just removed the motherboard and checked if it was far enough from the bottom of the case it seems fine i also checked the bracket of my cpu cooler but no metal is touching the motherboard but i repositioned it anyway so i put the mobo back in but it still restarts

Run diagnostics on RAM with memtest86 or memtest86+ Anupam