How do i update my video card drivers?

i have an acer aspire 5315 and when i play sims 2 it says my video card as stop worker, first do i need to update my video card, and second when can i update it, i looked on the acer site and foudn nothing but i dunno what im looking for, also when it says do this update i followed all the instructions and it didnt even have the update on the windows update, also there was one to do it manually and that didnt do it either, someone help me please :(|||Try going to the video card manufacturer for the newest drivers. Go to start---run----dxdiag to find out what card you have.|||u go to the Nvidia or ATI website and go to download drivers|||Go to Start/All Programs/Accesories/System Tools/ System Info. Find the manufacturer and type of video card in your computer. Write it down. Go to the manufacturer's website and find a link to download/ update drivers.