174 Glossary
video resolution — See resolution.
virus — A program that is designed to inconvenience you or to destroy data stored on
your computer. A virus program moves from one computer to another through an
infected disk, software downloaded from the Internet, or e-mail attachments. When
an infected program starts, its embedded virus also starts.
A common type of virus is a boot virus, which is stored in the boot sectors of a floppy
disk. If the floppy disk is left in the drive when the computer is shut down and then
turned on, the computer is infected when it reads the boot sectors of the floppy disk
expecting to find the operating system. If the computer is infected, the boot virus may
replicate itself onto all the floppy disks that are read or written in that computer until
the virus is eradicated.
V — volt — The measurement of electric potential or electromotive force. One V
appears across a resistance of 1 ohm when a current of 1 ampere flows through that
resistance.
W
W — watt — The measurement of electrical power. One W is 1 ampere of current
flowing at 1 volt.
WHr — watt-hour — A unit of measure commonly used to indicate the approximate
capacity of a battery. For example, a 66-WHr battery can supply 66 W of power for
1 hour or 33 W for 2 hours.
wallpaper — The background pattern or picture on the Windows desktop. Change
your wallpaper through the Windows Control Panel. You can also scan in your favorite
picture and make it wallpaper.
write-protected — Files or media that cannot be changed. Use write-protection when
you want to protect data from being changed or destroyed. To write-protect a 3.5-inch
floppy disk, slide its write-protect tab to the open position.
WXGA — wide-aspect extended graphics array — A video standard for video cards
and controllers that supports resolutions up to 1280 x 800.
X
XGA — extended graphics array — A video standard for video cards and controllers
that supports resolutions up to 1024 x 768.
book.book Page 174 Tuesday, July 3, 2007 12:31 PM