ClamWin is a free, open source antivirus software for Microsoft Windows. It provides a graphical user interface to the ClamAV (Clam AntiVirus) engine.

ClamWin Free Antivirus is licensed under the terms of the GNU General Public License and can be downloaded from the official website for no charge.

Features

Scanning scheduler.

Automatic virus database updates on a regular basis.

Standalone virus-scanner.

Context menu integration for Windows Explorer.

Add-in for Microsoft Outlook.

A portable version that can be used from a USB flash drive.

There is also an extension for Mozilla Firefox that uses ClamWin Free Antivirus to scan downloaded files for viruses (currently only supports Firefox 1.5).

Real-time scanning

ClamWin does not yet automatically scan files as they are read and written. This feature is planned for inclusion in the next major version update. However, this feature has been claimed to be in development since at least 10 December 2005. It is currently possible to add this functionality by using Winpooch.

Efficacy

In the 23 April - 10 May 2007 test performed by Virus.gr, ClamWin version 0.90.1 detected 47.95% of all threats and ranked 39th out of 53 products tested.