Get a new graphics card. Try a Radeon 9600.
I wanna run HL2 and doom3 better. I have a laptop with a2.4 ghz pentium4, 512mb RAM, 80 Gb hard drive and a Radeon mobility 7500. I takes forever to load these games and they hang up. all graphic qualities set to low. what would help. Increase RAM? Bigger faster hard drive? external HD to store games and apps freeing more space on the laptop HD?