Resetting a Dell Inspiron to the factory settings allows the user to restore the Dell Inspiron to the original operating condition as if it was just taken out of the box. Dell system includes a restore utility called 'Dell Symantec System Restore' to reset or restore your Dell system to factory setting. Also get here how to make Dell laptop run faster.
This utility is convenient because you're not forced to use the Windows startup CD to restore your computer.
Find below Dell help guide to reset your Dell laptop/computer to factory setting -
Step 1: Before reset any Dell Inspiron laptop, backup your all important data and programs, otherwise you may lose it. It is recommended to use an external storage device for your entire data backup, so that you couldn't lose it in any sudden occurring issue…Also find here Dell help guide if bluetooth problem in Dell Inspiron 1525 laptop.
Step 2: Remove any other unnecessary external drive and restart your Dell Inspiron laptop.
Step 3: Press 'F8' key continue until 'Advanced Boot Options' wouldn't be appear.
Step 4: Use your keyboard arrow key to select 'Repair Your Computer' from the list and hit 'Enter'.
Step 5: Now click 'Next' and login as the administrator account.
Step 6: Click 'Dell Factory Image Recovery and Data Safe options', select your language option and click 'Next'.
Step 7: Click the check box 'Yes, reformat hard drive and restore system software to factory condition' and click 'Next' to start Dell Inspiron reset process….Also find here why Dell laptop randomly shut down?
This process will erase all your previous changes that have been made to the Dell Inspiron laptop and reset the configuration settings to factory setting.