If you're still having trouble, please run a dxdiag: hit Windows key-R, enter "dxdiag" without quotes, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, upload it to a filehosting site (the free version of Pastebin is fine) and link it here.
Please also post the first 40 or so lines of deviceconfig.log, inside Documents\Electronic Arts\The Sims 3. (Stop where "Options" starts.) You can just copy and paste the info into a reply here. Your user and computer names will be about 20 lines down, so delete those if you want; the file doesn't contain any other identifying information.
