Free Antivirus tools

From my work reviewing them ...

• AVG: When I used this software two years ago, it was annoying because AVG would do a full system scan EVERY DAY or no scan at all. I thought that was just a waste of resources.
• Avast: Excellent but I always turn off the tool that creates a file repair sequence. Not necessary if the virus program effectively prevents viruses in the first place.
• Comodo: Comes with an integrated firewall, very customizable, and won many awards. Its what I use on my system but many of my users are annoyed by it because of its complexity.
• ClamWin: Its slow because it checks absolutely every file. It also picks up some false-positives, but then so does Comodo. I definitely use the Mac version to check files that I pass around and when I troubleshoot with my portable programs keychain.

Freeware Genius had a writeup on this.