System doesn\'t boot

Use the Clear CMOS jumper on the motherboard to reset it to defaults.

Normally this is 3 pins, and the jumper will cross 2 of the 3, you just move it one position over (so instead of pins 1-2 its now on pins 2-3). Wait 20-30 seconds, then put it back in it's original place. Power up the computer.

95% sure your machine will start again.

Chances are you've exceeded the max clock speed at the selected VCore, raised the PCI bus too high, or set the memory frequency too high (or a combination) by raising the front side bus by a margin of over 25%. Before raising FSB it's required that you watch or lock those values.

Older P4 boards don't have as many overclocker friendly features as the new boards, hence why it probably just sits there doing nothing.