Supposably a 'good brand' CD should last about 20 or so years. But I have had one go bad when it stuck to the silly plastic sleeve I put it in (Don't Use Plastic Sleeves!) and one in a standard case dated about 2000 will no longer read some of the files including a store bought collection of textures for DaCort's robe set. It'll try to read them but then locks up the system. That CD did work at one time when I reloaded but who knows what happened...? It's like my instructor said on day 1 of Computer 101 (1986): "Always back up your files, then make back ups of your back ups. And if your really serious, back those up too...."