How to get More FpS in games Without lossing details ???

[purav]

I am not having an powerfull machine to run the latest games on my system , And right now i can't upgrade to higher end machine due to financial problem

so is there is any software avaliable which can boost my system performance in Games so that i can get more FPS without lossing In Game Details ..

I have installed Intel Application Accelator on my system and it has given good results , So is there is any such other such software avaliable which can really reduce the load on Processor so that one can get good performance in Games .................................................. ..

My sys config is :--------->

Intel P - III 700 mhz (This is where problem is , Too slow for latest games ???)
Intel 815 EPEA 2 Mobo. .(No overclocking Support form intel )
Geforce 2 Mx 400(64 Mb) Detonator 40.41 installed (overclocked)
Windows XP pro .
Intel App Acc 2.2.2