100 AppendixChanging the Boot SequenceThe boot sequence, or boot order, tells the computer where to look to find the software needed to start theoperating system. You can control the boot sequence and enable/disable devices using the Boot Order pageof system setup.NOTE: To change the boot sequence on a one-time-only basis, see "Performing a One-Time Boot" on page 100.The Boot Order page displays a general list of the bootable devices that may be installed in your computer,including but not limited to the following:• Diskette Drive• Internal HDD• USB Storage Device• CD/DVD/CD-RW drive• Modular bay HDDNOTE: Only devices that are preceded by a number are bootable.During the boot routine, the computer starts at the top of the list and scans each enabled device for theoperating system start-up files. When the computer finds the files, it stops searching and starts theoperating system.To control the boot devices, select (highlight) a device by pressing the down-arrow or up-arrow key, and thenenable or disable the device or change its order in the list.• To enable or disable a device, highlight the item and press the space bar. Enabled items are precededby a number; disabled items are not preceded by a number.• To reorder a device in the list, highlight the device and press either to move the device up the listor to move a device down the list.Boot sequence changes take effect as soon as you save the changes and exit system setup.Performing a One-Time BootYou can set a one-time-only boot sequence without entering system setup. (You can also use this procedureto boot the Dell Diagnostics on the diagnostics utility partition on your hard drive.)1 Shut down the computer through the Start menu.2 Connect the computer to an electrical outlet.3 Turn on the computer. When the DELL logo appears, press immediately. If you wait too longand the Windows logo appears, continue to wait until you see the Windows desktop. Then shut downyour computer and try again.4 When the boot device list appears, highlight the device from which you want to boot and press.The computer boots to the selected device.The next time you reboot the computer, the previous boot order is restored.