New viruses pop up more and more frequently all the time. Also they spread much faster than they used to several years ago. The main problem is not to add their detection into the antivirus product but the fact that most of the users do not use any antivirus program at all or they still have some ancient version which they have got together with their computer for free.
 

Avast Home Edition is free antivirus software for home or non-commercial use. It scans for viruses, worms, and Trojan horses. Avast scans on demand and can be scheduled for a boot-time scan. It protects e-mail, instant messengers, and P2P clients. It maintains a virus chest. True incremental updates (well under 100KB) based on iAVS technology updates virus definitions at least twice a week.