Help! Problem with ATI 9600 PRO

hey guys!
can you help me with my problem. it seems that my ATI card 9600 pro is having problem with most games. in most games(old and new) my computers hungs-up after i run it
i have an intel p4 2.8e processor and 512mb ddr400 ram but i still experience program lags and worst it hungs.

need your enlightenments guys…