Viruses, worms, Trojans, and spyware are all major problems confronting internet users today. What made getting antivirus software more complicated is that many viruses and spyware pretend to be an antivirus software.

With this in mind, we have listed the most popular free antivirus software packages, ranked by popularity, as determined by third-party traffic monitoring sites.

Title Description
Avira AntiVir Personal Edition Classic Guards against viruses, worms, and Trojans. Also detects and deletes rootkits. Paying versions are also available.
avast! Free Antivirus A full-featured antivirus package that supports 64-bit Windows and is available in many languages.
AVG Anti-Virus Free Edition Popular anti-virus software from Grisoft. Commercial versions are also available.
Ad-Aware Free Antivirus+ Popular anti-spyware product with over 400 million downloads.
Spybot - Search and Destroy Popular anti-spyware and adware remover.
ClamWin An open source free antivirus program for Windows systems.
Panda Cloud Antivirus Panda Security's free antivirus offering for home users.
Malwarebytes Industrial-strength program that removes malware from your machine.
Norton Antivirus A full version of the popular Norton Antivirus product that you can try for free for a limited time.
Spyware Blaster A free spyware prevention program that helps keep your system spyware-free and secure, without having to remain running in the background.