Overclocking a PC?

Hello !

I am a real newby. I’d like to overclock my computer (an HP Pavilion) and I have no idea how I can do that.

I'm pretty sure that I can overclock it without any heat problems – when I put my hand on it, even after being on and running for a while, it's cold to the touch.

Is there different ways to overclock different computers, some software or driver to download?

Please, I need some help!

Thx.