Peter Norton of the fabled Norton antivirus program once said that there was no such thing as a computer virus and considered the whole idea some sort of hoax. Whether this is fact or fiction, keep your antivirus software up-to-date so your computer is protected. The consequences of catching a virus can include: causing your computer to be very slow, loss of productivity, and losing your personal data. If you have no antivirus, a free program is AVG Antivirus.