gp4 too slow

hi,
when i try to play gp4 in my old pentiumIII 750mhz, 384mb ram and a geforce with 64mb and 128bits the game runs very slow!!!!
the system requiriments shows i´m ok to play in that machine... what´s going on?
In my new pentium4 it works perfectly, but the pentium 4 is my all familly computer and the pentium3 stays in my bedroom for myself to use...
i dont wanna stops a race to let may family use the pc, so, i need some help...
pls..


- Nelson Piquet - F1 WORLD CHAMPION 81/83/87 -

Well, that computer is ok with the original gp4, but if you've updated it, it's "normal" it's slow...