I recommend against overclocking.
From what I've read you won't get that much of a performance increase and it will likely make your computer unstable (I.E likely to crash a lot and not run right when booted up).

A few more things I just thought of to say:
I've read that you can actually damage the motherboard by overclocking it.
I think in part because some overclocking settings actually increase the voltage going to the components when they aren't designed to handle any more voltage. More voltage means more heat and more heat means without extra cooling the components being overclocked will overheat and may get damaged.
Sometimes even with extra cooling you can't always be sure components won't be damaged.
Also I got a computer off of eBay that came overclocked by the person who built it (It was listed that way, I figured I would try it and see what happened) and the first thing that happened when I turned it on and Windows loaded was a stop error or BSOD as it's more commonly known.
I turned off all the overclocking settings and the machine runs just fine now.
Some people get lucky and the overclocking works for them but from all I've read and seen it isn't worth the risk of damaging components and creating an unstable machine.
Oddly enough though some people do think it's worth the risk.

@jd2066, more voltage does not mean more heat, more current (amperage) does.

Yes, but unfortunately it doesn't quite work like that.
There are chips (or circuits) that control the voltage and chips (or circuits) that control the current, so anything is possible

To properly overclock, you need to invest in more cooling solutions. Some people go so far as to use liquid cooling. It's really not a good idea unless you're into modding your hardware as well.

@Lighthouse: Ok. I don't really know how the overclocking affects heat. I was just assuming it was the increased voltage. I should have researched that idea before posting it.

And quantum is at work when you may, or may not, hit the floor

I luv it ! Finally a forum with a sense of humor in it's members !

lol u guyz are having fun going into all this science. I thought this is a computer forum lol:).

anyway thanks for ur says, yeah i should not go forward with overclocking. I wanted to see if there was a significant increase in performance by overclocking but since my desktop is not the very HIGH technology type i cant. Besides it only has like one fan. :)

If you're interested I'll repost the links