A "very unfortunate coincidence" when updating virus signatures and scanner software caused the free ClamWin (ClamAV for Windows) virus scanner to run amok and move large numbers of files into quarantine on Windows systems. On the ClamWin forum, various users reported that 25,000 files, including system files, were moved into quarantine as a result – more or less the entire system.From Free ClamWin virus scanner moves most of Windows into quarantine - The H Security: News and Features
The flaw has reportedly been fixed, but some users are struggling to restore their systems. The ClamWin developers have produced a batch file that allows the files to be restored to their original locations, but the batch file uses the information stored in the ClamScanLog.text file to do so – and the log file has a size limit of 1 MByte. For some users, this potentially means that numerous file paths won't be listed, so they will have to manually restore the files to their original locations.
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Free ClamWin scanner moves most of Windows to quarantine
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On top of that one of my friends who is quite knowledgeable reported that the latest upgrade also removes older versions of the software if you have decided not to upgrade to the latest version. Some sort of a poison pill on top of the other problem. 
Whatever happened to the concept of testing your product before releasing it ???? 
I think that died in the late 80's when the PC became popular in corporate environments as a result of "business" professionals making computer purchasing decisions rather than "IT" professionals and Microsoft's competitors learned that spending time on costly efforts such as "testing" or "documentation" left them falling behind in sales. RIP DEC
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