Bad FPS in source games

[Zerograv]

Ok looking at my rig i should have a good FPS in source based games (the older ones HL2, CSS etc etc)

CPU: Intel celeron 2.60Ghz Overclocked to 2.9ghz
Ram: 1GB DDR
GPU: Nividia GeForce 6600 LE 256MB
Anything else you need just ask

But whenever i play i get a FPS of 15 max and ive tried re-installing HL2 to various config files to lowering the dxlevel and nothing ever seems to work so help please

 

[Zerograv]

I think i posted this in the wrong bored