Avast Home Edition is a complete ICSA certified. Avast includes the following components: On demand scanner with skinnable simple interface, just select what do you want to scan in which way and press the Play button; On access scanner, special providers to protect the most of available e-mail clients; Instant messaging- ICQ, Miranda; Network traffic - intrusion detection, lightweight firewall; P2P protection for Kazaa, BitTorrent; Web shield - monitors and filter all HTTP traffic; NNTP scanner -scans all Usenet Newsgroup traffic and all operations with files on PC; Boot time scanner - scans disks in the same way and in the same time as Windows CHKDSK does.
Version 4.7.1043 improves Boot time scanner, adds support for few new packers, and fixes few small issues.
Avast! Antivirus - http://www.avast.com
Pros: Just because it's free doesn't mean you have to compromise on quality. Avast does all the anti-virus work by itself, using it's comprehensive yet powerful resident scanning and on-the-go shields to provide you with full real-time protection. It has all the features of an expensive program, such as an accurate/outstanding detection abilities, plus a nice pack of neat features working together to protect you any harm from e-mails, surfing to file-sharing and such. In my opinion avast is definitely the best choice for free anti-virus if not rivals those of the commercial ones.
Pros: Avast is far more better than avg,having better interface,faster database update,less bugs than AVG,with powerful boot time scan,