How to boost performance of Dell Latitude D620

I bought myself a Dell Latitude D620 that is a little slow in performance so what improvements can be made on this? A friend of mine told me that it was a easy job for him to boost this machines performance but he is not here & had gone for studying far away and i dont know how to do this properly. I am new to overclocking & have some minor knowledge of clocking that i did with my stationary Pc's. So if someone could guide me at the right direction would really be great. Computer spec is Dell Latitude D620 with 1.6 GHz & 1 gb ram & windows xp pro with sp2. Thanks in advance.

I cant assume why it is slower without knowing what is it running software or hardware wise that you need? Windows xp sp2 with processor & 1 gb ram should not be a problem for you until you have many software running at background & maybe also auto running at startup. So for a start I suggest you to follow this steps in this article which will help you a lot firstly.

Thanks but that didnt help me at all, now my another question is whether if i can put a graphic card of ati on this machine? Thanks