i think sum1 had posted about this aged ago

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anyway here is a small test which you can do in case you are not sure if your anti virus program is working fine or not.
#1 Open Notepad and paste this string into it ( without double quotes )
<">#2 Save it and as soon as you do your antivirus real time protection should be able to detect it. In case you have disabled the real time protection run a scan for this file.
This file actually is a dummy virus which simulates like a virus which is provided by EICAR for distribution as the �EICAR Standard Anti-Virus Test File�, The file is a legitimate DOS program, and produces sensible results when run (it prints the message �EICAR-STANDARD-ANTIVIRUS-TEST-FILE!�). You can read more on this at EICAR Antivirus Test File.
For those of you who say your auto scan doesn�t detect it� I have tried on a few anti-virus� If your anti-virus doesn�t scan text files under real time then it will not detect it until you do a system scan. To make it detect it real-time you need to tell your real-time scan to scan all files, not just �smart� file scan. You can test it by saving as an exe or other format that is on the auto detect file list.