What is a virus killer?
Virus killer software (also called anti-virus software) protects your computer against viruses. Analagously to human diseases, these are programs that install themselves on your computer in secret, often to cause damage and/or use your network connection to replicate themselves. The virus killer software identifies the virus and stops it from installing on your computer. As there are new viruses developed every day, it is really important that your virus killer is up to date.