I have sims 2 university & pets. To be able to play I cannot put in sims 2 original disk or university one, it says put in sims 2 pets. When I do this, it SOMETIMES loads up, and most times doesn't. I then go to all programs, ea games etc and click on it, but it comes up as saying 'Make sure you have sims 2 pets disk in the drive', even though I do. What can I do to make it stop this and just load up normally?other disks work fine, and my sims disk does not have any scratches etc on it - anyway if it did it wouldn't load up occasionally ...