avast! 4 Home Edition is a freeware antivirus software for home noncommercial use. It scans for viruses, worms and Trojans. avast! obtained multiple VB100% award in Virus Bulletin reviews.  
avast! scans: On Demand - with Skinnable Simple Interface, during Boot Time and On Access. It protects E-mail, ICQ, mIRC, Kazaa etc. It maintains Virus Chest.  
True incremental updates based on iAVS technology update virus definition at least twice a week.