timmcat,
The GeForce4 MX420 is holding your system back. You should look at upgrading that card to either a GeForceFX 5900XT w/128Mb or a Radeon 9800Pro w/128Mb.
Take Care,
Richard
P.S. While using the GeForce4 MX 420, make sure you install the latest
nVidia ForceWare Drivers