Sims 3 Problem! Help?

I have been playing Sims 3 on this laptop for a year, and never had any problems. Yesterday, I double-clicked Sims 3 to bring up the launcher, so I could play. The second I did that, my whole computer screen goes dark black, and starts flashing back and forth from dark black to dark grey. I can't exit out or anything, and end up having to force shut off my laptop (by holding the power button down until it shuts off). Thinking it had to do with my CD/DVD drive, I ran the Sims 2. it works perfectly. Any ideas why this is happening?