|Still not an awful lot of RAM for gaming. Judging by the amount, you're probably using onboard video rather than an actual video card. 512MB RAM installed - 32MB used by onboard video = 480MB left for the system.|
Anyhow, since you said SIMS 2 had been working OK, I would suspect the new RAM is defective. You (or your PC dude) can test it with a program called memtest86. If any errors are detected, the RAM is bad & will have to be replaced.