Monster4Market :
I want to run games that which needs a good CPU.
Then you need a good CPU, not an attempt to overclock a slow old one. If you had something like an E8400 at least you have something half-way good to start on. Plus you don't want any chance of the CPU getting damaged which is impossible to guarantee even for a small overclock that will do nothing to help you. To get to any noticeable speed improvement you need at least a %25 overclock and with that slow CPU that won't get you much at all. Since you have no money on a faster used CPU, means you have no money on a better cooler which is needed if you want to minimize any chances of damage to the CPU.
I'm assuming with that weak CPU you also have a weak video card, which would mean you need to upgrade that as well, and probably the power supply and maybe even the case.
Post your full specs and exactly what games you want to play.
You can check your system here www.systemrequirementslab.com/ against the games you like.