If you don't already have antivirus software installed on your computer, you're playing Russian Roulette with the Internet.
Antivirus software protects your computer from malware, short for "malicious software." Malware is the general term used for software that infiltrates your computer system and slows it down or gathers private information.
There are a few different types of programs you can use to protect yourself against viruses and malware. A full-scale antivirus program scans your computer for existing threats, cleans them, and then protects your computer from new attacks. Remove-only software isn't preventative, but it is essential if your computer is already infected and won't let you install a full-fledged antivirus software program.
Check out the gallery above for a list of free antivirus software. Do you love an antivirus program that we missed? Let us know in the comments below.