How can i restore my dell dimension to factory setting

To restore the settings you have to follow the steps

Instructions

Windows XP
1. Step 1 Disconnect all peripheral equipment that is attached to your computer such as printer, scanner, external hard drive and memory sticks.
   
2. Step 2 Restart the computer. After the Dell screen appears on the monitor, hold down the "Ctrl" key and press the "F11" key. If the Windows XP screen appears before you can finish this step, wait for the computer to finish rebooting and restart the computer again.
   
3. Step 3 Highlight "Restore" in the Dell PC Restore window by using the tab button. Hit "Enter."
   
4. Step 4 Highlight "Confirm" in the restore warning box by using the tab button. Hit "Enter." This will start the system restore process. Do not attempt to turn off the computer during this process or vital system files may be damages and you will not be able to restart your computer.
   
5. Step 5 Click "Finish" in the box that notifies you that the restoration has been successful.
   
6. Step 6 Hit "Enter" to restart the computer. The computer has been restored to the original factory settings.
   
Windows Vista
7. Step 1 Disconnect all peripheral equipment that is attached to your computer such as printer, scanner, external hard drive and memory sticks.
   
8. Step 2 Restart the computer. After the Dell screen appears on the monitor, press the "F8" key. If the Windows Visthow can i restore my dell dimension to factory set - mag-glass_10x10.gif/images/mag-glass_10x10.gif" alt="mag-glass_10x10.gif" class="h_mi" /> screen appears before you can finish this step, wait for the computer to finish rebooting and restart the computer again.
   
9. Step 3 Highlight "Repair Your Computer" by using the down arrow key in the Advanced Boot window. Hit the "Enter" key.
   
10. Step 4 Click "Next" after selecting a language. Log into the computer as an administrator. Click "OK." Choose "Dell Factory Restore." Click "Next."
    
11. Step 5 Check "Yes" next to the reformat the hard drive and restore factory settings option. Click "Next" to start the restoration process. Do not attempt to turn off the computer during this process or vital system files may be damages and you will not be able to restart your computer.
    
12. Step 6 Click "Finish" in the box that notifies you that the restoration has been successful. The computer will automatically restart itself to its original factory settings.