What motivates people to create computer viruses?

[alexa n]

well people do that because their haters...

hope this information helps:
A program that infects a computer by atttaching itself to another program, and propagating itself when that program is executed. A computer can become infected by files downloaded over a network, or by the installation of new software or floppy disks that are infected with viruses. Some viruses are only pranks, and perform harmless actions like displaying a screen with a joke message on it. Others can destroy files or wipe out a hard drive. To avoid damage from viruses, write-protect the boot disk and other important disks, check new software or disks for viruses, and have virus protection software installed on the computer at all times. Disinfectant programs must be updated periodically because new viruses get into circulation over time. There are some virus protection programs available on the Internet for free. Disinfectant for Macintosh, written by John Norstad of Northwestern University, is freeware; McAfee Anti-Virus for PC is a shareware program. Knowingly spreading a computer virus is a crime punishable by law. See also Trojan horse and worm.