Troubleshooting 143If only part of the display is readableCO N N E C T A N E X T E R N A L M O N I T O R —1 Shut down your computer and connect an external monitor to thecomputer.2 Turn on the computer and the monitor, and then adjust the monitorbrightness and contrast controls.If the external monitor works, the computer display or video controllermay be defective. Contact Dell (see "Contacting Dell" on page 165).DriversWhat Is a Driver?A driver is a program that controls a device such as a printer, mouse, orkeyboard. All devices require a driver program.A driver acts like a translator between the device and any other programs thatuse the device. Each device has its own set of specialized commands that onlyits driver recognizes.Dell ships your computer to you with required drivers already installed—nofurther installation or configuration is needed.NOTICE: Your Drivers and Utilities media may contain drivers for operating systemsthat are not on your computer. Ensure that you are installing software appropriatefor your operating system.Many drivers, such as the keyboard driver, come with your Microsoft®Windows® operating system. You may need to install drivers if you:• Upgrade your operating system.• Reinstall your operating system.• Connect or install a new device.Identifying DriversIf you experience a problem with any device, identify whether the driver is thesource of your problem and, if necessary, update the driver.