Check out this website: http://www.clamwin.com
ClamWin Antivirus is an Open Source (free) Virus Scanner Toolkit for Microsoft Windows NT/98/Me/2000/XP/2003. It provides User Interface to Clam AntiVirus scanning engine.
ClamWin Antivirus Features include:
* Scanning Scheduler;
* Automatic Virus Database Updates. ClamAV team updates Virus Databases on a regular basis and almost immediately after a new virus/variant is out;
* Standalone Virus Scanner;
* Context Menu Integration to Microsoft Windows Explorer;
* Addin to Microsoft Outlook.