Definitions

• A virus is a program that infects computer files with the intention to steal data or harm the system. Spyware is a program that is usually installed without the knowledge of the user. Spyware collects personal information and sends it to a central source to be sold to advertisers or identity thieves. Malware is a blanket description of any program that intentionally does harm to a computer.
  
  

Software Prevention

• Anti-virus software runs in the background of a computer. The software detects changes in critical system files or suspicious behavior. Many anti-virus programs also scan downloaded programs and e-mail to prevent viruses from entering a system. Anti-spyware software runs in the background looking for either known threats or suspicious behavior from software on the computer.
  
  

Software Removal

• Anti-virus and anti-spyware programs run system scans either on a schedule or on-demand. The programs use a list of known bad or infected code called definitions. The software compares the files on the computer to the definitions to detect viruses. New viruses and spyware are released on a daily basis so definition files are constantly updated.
  
  

Best Practices

• Always make sure that important files are backed up regularly. Install anti-virus and anti-spyware software on computers and have them update and scan regularly. Do not open e-mail attachments if you are not sure of their source. Scan e-mail attachments before opening to prevent e-mail viruses. Do not visit questionable websites. Always download Windows critical updates as soon as they are made to prevent viruses from exploiting system vulnerabilities.
  
  

Products

• Retail anti-virus and anti-spyware programs include Norton Anti-Virus, Norton 360, McAfee Anti-Virus, Computer Associates Anti-virus, and AVG Internet Security, among others. Free anti-virus software includes AVG Free Edition, Avast! Anti-virus Free, and Avira Antivir Free among others. Free anti-spyware software includes Spybot Search and Destroy, Lavasoft Ad-Aware, and Malwarebytes Anti-Malware.
  
  

Considerations

• Some viruses and spyware programs require special removal tools. These tools target specific threats and are created by companies such as Symantec. Some viruses, known as boot viruses, have to be removed with a bootable anti-virus program. The boot virus infects the first sector of a hard drive and can not be removed through a normal scan in windows.