My Dell PC can not find Hard Disk and CD-ROM this moring. A Dell support engineer told me the method to clear the BIOS.
1. Reboot the PC, press F2 to enter setup
2. light up all of the three ligths on the upright of the keyboard (num lock, caps lock, scroll lock)
3. Press Alt+E
4. Press Alt+F
5. Press Alt+B
the PC reboot, and reconfigurate, then everything is ok.
Any more problem call Dell support at 800-858-2437
Hope it is helpful when you meet the same problem.
