A virus is a piece of software that infects a computer. After the virus code is written, it is buried within an existing program. Once that program is executed, the virus code is activated and attaches copies of itself to other programs in the system. Infected programs copy the virus to other programs. The effect of the virus may be a simple prank that pops up a message on screen out of the blue, or it may destroy programs and data right away or on a certain date. It can lie dormant and do its damage once a year. Obtaining a copy of the most current Virus protection software, and then updating that program periodically is the most effective defense from viruses.
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