Following is a list of antivirus software that can be downloaded free of cost:
Ad-Aware Free Anti-Malware
With behavior-based threat detection and integrated real-time monitoring, Ad-Aware focuses on core consumer security needs.
Avast Antivirus Home
Avast Free Antivirus is based on multiple protective layers that work together to provide security.
AVG Anti-Virus Free Edition is an anti-virus application that rivals commercial version such as Norton.
Avira AntiVir Personal
Avira AntiVir Personal Free Antivirus is a comprehensive, easy to use antivirus program, designed to offer reliable free of charge virus protection to home-users only.
Malwarebytes’ Anti-Malware is a high performance anti-malware application that thoroughly removes even the most advanced malware and spyware.
Microsoft Security Essentials
With Microsoft Security Essentials Beta, you get high-quality protection against viruses and spyware, including Trojans, worms and other malicious software.
SuperAntiSpyware, a next generation product, with its Multi-Dimensional Scanning and Process Interrogation Technology will detect spyware and remove over 1,000,000 pests such as Vundo, ZLob, SmitFraud, WinFixer, VirusRay, and VirusHeat.