You go into the BIOS, usually by hitting the delete key ("Del") during boot. Then you go into either Adv. Chipset Options, Frequency/Voltage Control, or possibly another one of the menus (varies depending on the motherboard, check your manual). Then you find the FSB option. Increase it by about 5. Save your changes and let the computer boot into Windows. Then run either SuperPi or 3DMark2001SE to test stability. If it is successful, go back into the BIOS and increase the FSB by 5 more. In the event that you no longer can increase the FSB, try raising the voltage on the RAM and the VCORE (be careful with this) or increasing the multiplier. If at any time the computer fails to boot open up the case and reset the CMOS jumper.