Computer viruses are pieces of software which attach copies of themselves to one or more files in a computer system. Like viruses in biology (e.g. the flu virus), they may spread from file to file, and from computer to computer. When they attach themselves to your files they can change the way those files work or they can stop your computer from working properly. Some rare viruses may even damage or destroy your files.
Viruses are part of a class of software call "malware". Malware includes viruses, trojans, worms, spyware, key loggers and more. The writers of malware may have a benevolent intent, such as companies who write key loggers so your employer may know what you are up to, but by and large writers of malware seek to hold your computer hostage, destroy your computer or find a way to extort financial information from you.
Anti-virus software is software that intends on keeping the viruses and other kinds of malware at bay. Today most anti-virus software does a good job of protecting your computer, and if you keep your software up to date with the latest malware databases, by and large your computer will be fine. Keeping your database up to date will often be your greatest challenge.
The University of Nebraska at Omaha uses McAfee software to protect its computers from viruses and other malware. The University encourages its faculty, staff and students to use this software if they have a Microsoft Windows operating system. If you are a part of the University as a faculty member, a staff person or a student, you may download and install McAfee free of charge to your computer provided the computer is owned by you or the University. You can download the software from the University's install server. You will need to know your University network ID and password.
The server also provides you with instructions on how to install the software.
McAfee is not the only writer of anti-virus software. Microsoft recently released its own version of anti-virus protection, and there are numerous third parties which do the same. We list a few of these software packages below, and include anti-virus software for other operating systems as well.
Keep in mind, however, that the University only supports the use of McAfee Virusscan. If you have problems with software other than McAfee, you will need to contact support at the respective companies from which you buy your anti-virus software.
Symantec has a popular anti-virus package called Norton AntiVirus. It protects against viruses, worms and trojans, as well as spyware and other malware. It also helps protect you from malicious attachments you may receive from email, instant messeges, and more.
Some others include these:
ClamWin (an open source anti-virus package)
Apple OS X
The Apple OS X is a fairly secure environment based on the BSD (Unix) distribution. However, like all operating systems it, too, can become infected by viruses. The University does provide protection for Apple users with McAfee's Virex software. University faculty, staff and students may download this from the University's install server.
The solutions for Linux are fewer than for either Microsoft Windows or for Apple OS X, and the ones that exist generally are for businesses running servers. Kaspersky is one company that does provide anti-virus software for Linux workstations, as does F-Secure.