Number of free anti viruses instead of expensive anti viruses

Aviation . P. , Quick Heal , and Mac ऐfi such as Norton Anti expensive place free of viruses , there are many anti viruses are not reduced in quality in any way . Chief among these are the following

    Panda Cloud ऐँti viruses - http://www.cloudantivirus.com/en/
    Avira Personal Free ऐँti viruses ऐntivir - http://www.avira.com/en/avira-free-antivirus
    Maikrosoft Security Senshiyls -

    http://www.microsoft.com/en-in/security_essentials/default.aspx
    Avast Free ऐँti viruses - http://www.avast.com/free-antivirus-download
    Comodo Internet Security Premium -