What to do when you sims nightlife has no more space? Please help me!!?

Normally when I put my Sims nightlife disk in my laptop it automatically opens, but this time it didn't. I tried going to computer and clicking on it there but it wouldn't open, so even when I right clicked on it and said Install or Run Program it wouldn't open. But then I realized that whenever I scroll over it it says space free: 0 bytes Total Size: 6.74 GB. I can also click Open and when I do it shows all the files on the disk.Should I delete something there, and if so what? What should I do? Please help me ASAP!!