ClamWin is a Free Antivirus program for Microsoft Windows 7 / Vista / XP / Me / 2000 / 98 and Windows Server 2008 and 2003.
ClamWin Free Antivirus is used by more than 600,000 users worldwide on a daily basis. It comes with an easy installer and open source code. You may download and use it absolutely free of charge. It features:

* High detection rates for viruses and spyware;
* Scanning Scheduler;
* Automatic downloads of regularly updated Virus Database.
* Standalone virus scanner and right-click menu integration to Microsoft Windows Explorer;
* Addin to Microsoft Outlook to remove virus-infected attachments automatically.

Please note that ClamWin Free Antivirus does not include an on-access real-time scanner. You need to manually scan a file in order to detect a virus or spyware.
ClamWin Free Antivirus is based on ClamAV engine and uses GNU General Public License by the Free Software Foundation, and is free (as in freedom) software.