Icon for CD drive disappears and reappears every few seconds
Sounds like the CD drive is malfunctioning. This could be caused by many different problems, from partially detached cables inside the laptop to just a dirty CD slot and/or laser lens. One simple weird trick is to take a can of compressed air and give the CD slot a blow-out when not loaded with a disc. 

There are CD laser lens cleaning discs, including this version with a 3.5" floppy disc cleaner included!