How do I pump up a CPU's core voltage?

I'd like to pump up the core voltage on an unstable CPU I have (it sometimes
crashes while trying to load Windows XP and I'm having difficulties
unzipping large files. When I check the System using Control Panel, the
computer reports having an AMD Duron Processor that runs at 1.3 GHz. In
BIOS, the PnP settings inform me that the machine's processor is "Pro 2000+"
and that the machine's core voltage is 1.808. I'd like to raise the core
voltage to 2.0 to see if that improves my system's stability. However, I've
never overclocked a machine and I'm not sure what I have to do to the
processor in order to raise the voltage manually. I can't get it higher than
1.808 in BIOS. Does anyone here know of a website that could assist me in my
overclocking efforts?

-Rob