If you haven't done the deed yet:
Look in the C:\Documents and Settings\All Users\Application Data\Avast Software\Avast\report\aswBoot.txt file (XP location)
C:\ProgramData\Avast Software\Avast\report\aswBoot.txt (Vista, Win7 or later OS location), check this file using notepad for info on the scan/detections, etc.