Q&A: How do I use a different sims 3 disc to play?

Okay, so I have the sims 3, sims 3 pets, sims 3 night life installed. My friend let me download the sims 3 pets on my computer, but she needs it to play on her laptop as do I. Whenever I insert the night life to play, it says I need the pets disc. Is there anyway I can set it so that I only need the night life to play? Thanks.