Check the jumper on the back of the cd/rom or hard drive before you discard it . It should be set to Master before you discrd it. The jumper is a tiny clip that connects pins together. It is easy to pull this off and move it over to MA- master. Cable select can go out and seen like the cd/rom or even hard drive has died, when it actually has another rout of transportation for data. Cable select can burn out kind of like a fuse burning out. Master is another way for data to travel. just open the computer and look. This will cause alot of Hard drive errors such as can't boot into the Operating system or can't get my cd to play. It can even be intermitten errors not just total failure. Every one also needs to remember to Defrag and SCANDISK-Error checking for the hard drive. this will prolong the life. I would pull out the hard drive and slave it into another computer and run a scan disc on it.