Vista 64 video driver issue

Hello, I am running Windows Vista Home 64 bit on a Dell 1640. Recently my computer caught a virus and I had to reinstall Windows. The computer seems to be running almost back to where it was from the factory however I am having issues with my video driver. I play the Sims games and I have talked to their tech support. They tell me that my driver hasn't been updated since 2008. I have tried to update the driver from the Device Manager and it tells me it is up to date. I have also searched the Dell website and other sites and nothing I seem to find that should fix this problem works. I need some advice on what my next step should be, any ideas?