This is normally caused by a failed hard drive. What you should do to start is test your hard drives using the Dell diagnostics utility on your Dell drivers and utilities disc.
To test your hard drive using your Dell Drivers and Utilities disc: 1. Reboot your system. When you see the Dell logo, hit F12 to enter the boot menu. 2. Insert the Dell Drivers and Utilities disc in your CD/DVD drive. 3. Pick the option to boot from the CD/DVD drive. 4. You will be prompted to hit any key to continue booting from the CD/DVD drive. 5. You will be prompted to hit 1 to run the Dell diagnostics. You may see two such menus. 6. Select Test System. 7. Select Custom Test. 7. Use the arrow keys or mouse to select your hard drive. 9. Click Run Tests. 10. Write down any error messages.