Free Antivirus :
Avast Antivirus Free : https://www.avast.com/index
AVG Antivirus Free : https://free.avg.com/us-en/homepage
Avira Antivirus Free : https://www.avira.com/en/avira-free-antivirus
BitDefender Antivirus Free : https://www.bitdefender.com/solutions/free.html
Microsoft Security Essentials Antivirus Free : https://windows.microsoft.com/en-IN/windows/security-essentials-download
Top 13 Free Antivirus : https://freebies.about.com/od/computerfreebies/tp/best-free-antivirus.htm