Sims 3 Pets not launching

Hello guys!   Agh, well tonight has been frustrating. So, I have Sims 3 Base game and Sims 3 University Life bought, I didn't download from here. I downloaded Sims 3 Pets though. I actually downloaded the Sims 3 Pets along time ago and it worked FINE. But, my computer was wiped out clean. I did all the steps as slowly as possibly, and I did move the 2 files from the crack to the base game bin. So, I open the launcher, hit play, and nothing happens. The launcher disappears after clicking play and the game doesn't pop up at all. I even did it straight from the bin, still doesn't start!  I'm so frustrated because I know that it once always worked until my dumb computer got wiped out and now it doesn't! Hope you can help.