Tarryn_Higgins Please provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.
Please also open DeviceConfig.log, in Documents > Electronic Arts > The Sims 3, copy the first 40 or so lines (stop at Options), and paste them into a reply. You can delete your user and computer names, about 20 lines down; the file doesn't contain any other personal information.
It's not going to help to get your graphics card recognized if your GPU isn't even being used, so the first question is what the game is using.