There are many free antivirus software that we can obtain off the Internet. Here are some most excellent ones. Enjoy!

avast! 4 Home Edition

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

AVG

http://free.avg.com/ww.download?prd=afe

Avira

http://www.free-av.com/en/download/1/download_avira_antivir_personal__free_antivirus.html

bitdefender

http://www.bitdefender.com/site/Downloads/browseEvaluationVersion/1/42

CA

http://home3.ca.com/SubscriptCenter/MSTrialRegistration.aspx?cid=573

ClamWin

http://www.clamwin.com/content/view/18/46/

Comodo

http://antivirus.comodo.com/

Dr. Web

http://www.freedrweb.com/

Norman

http://www.norman.com/Support/auth/en

Rising

antivirus http://download.rising.com.cn/for_down/rsfree/ravfree08.exe

firewall http://download.rising.com.cn/for_down/rav2008/rfwz08.exe