I remember that, some time ago, I did an online scan on my computer and it detected viruses that were quarantined by the active/installed antivirus. isn't it possible that nod32 detected those 103 threats in the chest of avast? additionally, I have colleagues at work that received the "virus detected"-message from the antivirus and yet clicked on "run". more of that, on some ocasions I was near them, saw the message and told him to click "block the damn thing" but they clicked "allow run". sounds impossible? I have seen this. as for myself, i'm using avast free and i'm satisfied, never encoutered a problem.