Dell OptiPlex 755 User's Guide - Page 21

Before You Begin This chapter provides procedures for removing and installing the components in your computer. Unless otherwise noted, each procedure assumes that the following conditions exist: • You have performed the steps in "Turning Off Your Computer" on page 21 and "Before Working Inside Your Computer" on page 21. • You have read the safety information in your Dell™ Product Information Guide. • A component can be replaced by performing the removal procedure in reverse order. Recommended Tools The procedures in this document may require the following tools: • Small flat-blade screwdriver • Phillips screwdriver • Flash BIOS update program floppy disk or CD Turning Off Your Computer NOTICE: To avoid losing data, save and close all open files and exit all open programs before you turn off your computer. 1 Shut down the operating system: a Save and close all open files and exit all open programs. b In the Microsoft® Windows® XP operating system, click Start→ Shut Down→ Shut down. In Microsoft Windows Vista®, click the Windows Vista Start button™, , in the lower-left corner of the desktop, click the arrow in the lower-right corner of the Start menu as shown below, and then click Shut Down. The computer turns off after the operating system shutdown process is complete. NOTICE: Ensure that the computer and all attached devices are turned off. If your computer and attached devices did not automatically turn off when you shut down your operating system, press and hold the power button for about 4 seconds to turn them off. Before Working Inside Your Computer Use the following safety guidelines to help protect your computer from potential damage and to help ensure your own personal safety. Before You Begin 21