Which one is the best free antivirus software?

Try "Avast". It's free for the home version and so far it has worked perfectly for me. http://www.avast.com

Try AVG Free 8.0, Avira AntiVIr, or Avast. Dwell on any of them. For firewalls try Comodo Firewall. For additional protection, you may add Windows Defender (at Microsoft.com) or ThreatFire.

i used all of the softwares.......avast antivirus is not bad,but also not so gud.................... i found AVG & SPYWARE DOCTOR are the best antiviruses.......(remember trial version of this two antiviruses are not gud enough)u can dwnld pro version from here-- 1.spyware doctor(including serial)-http://www.mediafire.com/?zwajinivdgi 2.AVG antivirus(pro)-http://www.mediafire.com/?1mio2zxwfnd

http://www.free-av.com/ Norton is the most common answer because people have it. It comes pre-installed on many computers and most people don't know a thing about them. Norton is almost like a virus itself. Try deleting it from your computer and if you knew enough about them you would see that it leaves traces all over the registry. Even removing all strings from the registry is hard as it masks itself as many different things and self replicates if even one command string is left in the registry. No the best antivirus is still Antivir, One free year, with free update definitions. It isn't bulky and loaded with extra crap that will actually confuse your system (ie: additional firewalls/spyware etc..) Windows has built-in features for a firewall and it's own greyware/malware remover called windows defender. If you use more than one firewall they will create problems by interfering with each other.

Try downloading McAfee anti virus software. It works pretty good.