Dell Recovery OS disk does not work

My Dell HD failed so I replaced it. Now, all I have to do (I thought) is to load the re-install disk from Dell and it will run on its own….. WRONG
The reinstall disk does not read, the BIOS was changed to boot from the CD ROM. Is there a secret code Dell uses to make the disk readable? This is the second OS install disk they mailed out to me.
HELP!