Get free and works antivirus program

Avira Antivir Personal Edition Classic 

http://www.avira.com/en/download/index.html

PC Tools AntiVirus Free Edition

http://www.pctools.com/free-antivirus/download

ThreatFire AntiVirus Free Edition 3 

http://www.threatfire.com

Avast Home Edition 

http://www.avast.com/eng/download-avast-home.html

AVG Anti-Virus Free Edition 
http://www.download.com/AVG-Anti-Virus-Free-Edition/3000-2239_4-10320142.html?tag=lst-01