Change CPU Multiplier In Windows?

I have purchased a pentium 4 631 and wish to overclock it. I have used set fsb but i cannot get it past a certain point without crashing. I need a windows program that allows me to change the cpu multiplier or underclock the ram. I have tried overclocking in the bios but there are no settings, even in advanced mode. My motherboard is gigabyte GA-8S661FXM-775 (rev. 1.x) and I have tried to update the bios with no luck. I get the “BIOS size error please download the 4MB BIOS” error when I try to update with flash879 bundled with the update. There is no setting in the bios protecting the bios from being, no jumpers and no inbuilt bios update software on the bios despite what gigabyte says. I think this might be because I took the motherboard out of a lenovo 3000 j – series.
Any help would be greatly appreciated.