Today’s malware and viruses and intelligent enough. One of the first things they do after infecting a computer is to disable the security applications installed there and block their update process. In some of these cases you may not be able to use the GUI of Windows and in extreme cases you may not be able to even boot up your computer.

In such a situation, you may need some external security tools, which are stored on removal media like USB, Pen Drive or CR ROM, and use it to clean your computer.

There are many such Portable Antivirus applications, which can be downloaded freely and used to clean already infected computers. Most of them are stripped down version of their full-featured counterparts. They generally do not provide you real time protection and so, are not a substitute of your regular antivirus applications.

ClamWin is one such popular Portable Antivirus available for free download from the famous security vendor ClamWin.It comes with an easy installer and open source code. 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.

The best part of ClamWin is that it is Open Source and you can be absolutely sure that it contains no spyware or anything like that. But, it is sometimes criticized also for being open source, because the source code is available to the malware developers also and they can easily modify their code to bypass the detection tactics used by ClamWin.

Related: Ultimate List of Portable Antiviruses For Your USB

[This is a post from Silki Garg, who enjoys writing about Internet and PC Security Issues. Check out her latest article on Windows Security Tool - WinPatrol.]