Just a note, that last night Avast had an update, that resulted in numerous false positives of a trojan infection. It claimed that the file win32delf-mzg was a trojan, and that to move it to the virus chest.
However it isn’t and you’ll need to go to the avast support forums, for detailed instructions on how to restore those files. It will have made inoperable several key programs, like S&D Spybot, Adobe Reader, and others.
Mine showed up 75 infections, and so far, I’ve spent a few hours, finding out what it was, why many of my standard programs didn’t work anymore, and having to re-install several.
The restore was not that hard either, it is the re-install that is taking the time.
So for those who use Avast, CHECK HERE (support forum)
Good luck
Ian