Locate the cmos jumper. Use your manual to look it up on the print out of your motherboard. You have to move it over one position to keep 2 out of 3 pins covered with the system off and the power supply unplugged to reset the bios if your won't post after changing the cpu fsb to overclock. In the "advanced" menu, select "jumperfree configuration" and set the cpu overclocking to "manual". Then set the "cpu reference clock" to 240. Then set cpu overvoltage to "manual". the voltage selection should appear. 1.38 is the highest setting, which should be safe.