Try updating your graphics drivers.
If that doesn't help, could you post your Computer's DxDiag?
To gather a DxDiag on your computer, please follow the steps here: http://answers.ea.com/t5/The-Sims-3/HOW-TO-DxDiag-for-Sims-3-PC-Only/td-p/1049584/
I don't work or have any association with EA. I give advice to the best of my knowledge and cannot be held responsible for any damage done to your computer/game.
Please only contact me via PM when asked to do so.