Clockgen is a little tool to tune your motherboard's chipset. It allows you to increase or decrease the speed of the processor, ram,agp,pci,pci-e and fsb frequencies.
All you need is the PLL of your mother (check for a chip with the letters ICS in your board, look at the last number....or google it ) and you are done (Not all are supported)
This is the last release, which dates back from 2007, so this is for old PCs.
The soft is intended to be used on hard-to-overclock motherboards, so if you have a chance to OC through your BIOS or an official tool by the manufacturer, skip this post.
Results may vary, it all comes down to the Vcore voltage, RAM frequencies, motherboard quality, etc etc etc.

If you own a Northwood based Pentium 4, DO NOT use this tool, this processor can be damaged by ANY attempts to overclock it.

Make sure to research before you do anything, overclocking can damage your hardware.