Cannot install Sims 2 Fun with Pets

I have been playing the Sims 2 collection for about 5 years now, building families and towns. The disc that I have to run to play my game is "Fun with pets collection". Recently, it just stopped working. My pc seems to not be reading the disc. It would state "no cd/dvd-rom" everytime I attempted to play the game. I took my pc to a repair shop and had the drive replaced. I am still having the same issue, so I uninstalled the game, and saved it, thinking I could re-install it. Now it is not reading the disc at all. Is it possible that my disc is worn and will not work anymore? I have so much time invested. Anyone help? Could it still be the pc and not the game?