The Dell Optiplex 320 is a desktop with a mini-tower. Because of its comparatively smaller size, this computer is often used in office environments. If your Optiplex 320 is attacked by a virus that cannot be removed, you may want to reformat or reset the computer back to its original factory settings. You may also reset your Dell desktop if it has encountered a system error that cannot be fixed.
Click on the Start menu and select "All Programs." Click on "Accessories" and then select "System Tools."
Click on "System Restore."
Click to select "Restore my computer to an earlier time." Hit "Next."
Click on the very first restore point on the calendar. Note the restore points appear in bold in the calendar. Go through the calendar (year-by-year if needed) to locate the first restore point. This should also be the date when the computer was first reset. Single-click on this date. Hit "Next." Make sure there is no other restore points earlier than the date selected.
Wait till the System Restore resets your computer back to its original factory settings. The computer should restart by itself. Click on "OK."