|Did you check under my computer to see if the CD is listed there? If not, most likely it is a problem with your CD drive. You can try cleaning it:|
Also check to make sure the disc itself is clean and scratch free. Make sure all of the drivers you need for the CD drive are installed and up to date. For example, is an empty disc drive recognized in My Computer, or is there nothing?
In addition to this, you could try using an external CD drive and seeing if it works then, in which case there is something wrong with your hardware, and you should take it in or call dell customer support and have your computer repaired.