Overclock problem with graphics

[mel4159]

have core 2 duo 2.4 ghz 2gig corsair ddr2 mem ,gigabyte mainboard with 965 chipset, Nvidia 256mb memory graphics card. when set from 266 to 300 fsb the monitor doesn't work.computer works ok .Mel Gil

 

[agissi]

Lower the multiplier.

 

[slayorktc]

Check temps