Restore the Dell Latitude D820 laptop to the factory defaults to return the computer to the original operating condition. Use the restoration process only as the last effort in troubleshooting a major system error or severe damage caused by a virus. The Dell Latitude series comes equipped with a built-in recovery to make the restore process possible without the need for a supplemental software CD. Novice computer users can complete the restore process in a couple of steps.
Connect the external hard drive to the computer and backup any essential programs, files, documents, photos or other data on the computer's hard drive as the restore process will erase all the data stored to the disk. Insert the cable from the hard drive into one of the USB ports on the Dell. A folder will appear on the desktop associated with the external hard drive. Copy and paste any of the files you want to save into the folder. Right-click on the hard-drive folder and click "Eject" after you have copied all the files you want to save from the computer. Remove the hard drive's cable from the Dell.
Remove any external hardware devices from the computer as they may be damaged during the restore process. Disconnect any scanners, USB drives, external hard drives, flash drives, scanners, printers or MP3 players.
Restart the computer and press the "F8" key during the boot process to open the "Advanced Boot Options Menu." Use the arrow keys to select "Repair Your Computer" and press "Enter." The Windows Recovery Environment will open.
Click "Next" in the first System Recovery Options screen and click on "Dell Backup and Recovery Manager." Choose the "Dell Factory Image" in the list of backups (this is the factory default condition) and click "Next." Click "Next" in the Restore System window to begin the restore process.
Click the "Finish" button in the "Congratulations" notification that appears to restart your computer with the factory defaults restored.
- Thomas Northcut/Photodisc/Getty Images