can i enhance my setting?

[joeyko2000]

here is my system config:

P3 916MHz(up-freq)
256 SD RAM
GeForce FX 5600

others hardwares are quite stardard

i am sure my CPU and RAM are obsolete.
but my display is recently bought.
i am only running the game in a average setting.

how can i enhance my setting? (though software setting?)