well...here are my computer specs first of all: C2d E6750 /Ga-n650SLI-DS4L/2 gb kingmax ddr 800/thermaltake 600 W PSU/...this is what i did....i went to bios and i changed the fsb to 451 x 8 in sync with the memory/memory is at 901 mhz in 1:1 ratio with the fsb...i loosend the timings to 5 7 7 24 cuz the normal ones are 5 5 5 18 on my ram...i took the Vcore to 1.5 and ddr2 +0.3 to make the 2.1 and i upped the fsb voltage +0.1....then i saved to cmos and it enterd windows without a problem...ran orthos 2 hours no errors...i can play games and do everything..if i restart the comp no problem...BUT...if i shut it down and the turn it back on i just stops working and i have to reset the cmos...normal start:video card fan speed goes to 100% for 3-4 seconds the it comes back to normal and the system starts to run...if i oc,turn off the pc and the turn it back on...the video card starts as normal but it stay's like that and the system just halt's ultil i turn it off and reset the Cmos...does anybody know what's the problem? Thank You!