trying to upgrade pc

i have a athlonxp1800 756md 40gig 9600ati radeon not the xt one but the cheaper end card and yesterday i just bought a 19 inch monitor but at 1600x1200 it runs slow what can i do so it can run smooth upgrade my processor please help.

Run it at 1024x768 and turn down some details. The 9600pro isn't that fast considering you've only got an 1800+. You'll need something along the lines of a 2500+ and up to extract everything you possibly can outta that card.
If you want to run it at 1600x1200 upgrade both your cpu and radeon.

thanks i do that.