Theories

• Misconceptions about anti-virus software include a belief that it can catch everything malicious that could infect your computer. Catching malicious programs is not an exact science, and the challenge is ever changing. Another misconception is that you have to pay top dollar for an anti-virus program to be good. A number of free programs will do the same job as the big names, sometimes even better.
  
  

Function

• The primary function of an anti-virus program is to scan your computer for viruses that are already there or that may be present in incoming email, message attachments and downloads.
  
  

Considerations

• Your antivirus will most likely not catch malware (also known as spyware), which is different to a virus. To catch malware, you will need a separate malware/spyware program. Many good free programs can do the job.
  Never install a program that is forced on you or takes over your computer. The program you choose should be downloaded voluntarily by you.
  
  

Updates

• Your anti-virus program needs to update regularly. New viruses are abundant, and programmers have to work hard to stay on top of the malice. Your anti-virus program should update regularly on its own and in the background. If your anti-virus doesn't do this, or the company wants a subscription fee--skip it.
  
  

Verdict

• Good commercial anti-virus programs on the market include Norton and McAfee. The free program AVG does what commercial anti-virus programs do without the price. AVG also doesn't make you subscribe to a yearly service (as does Norton) and it updates its database as well as the others.