bg,
When Avast notifies you of a potential virus infection, it normally gives you options to Delete, Move or Repair.
If not, open the Avast virus scanner and run a full scan setting the scan to Thorough including Archived files (this is done using the little pop up tabs you will see when you select which drive you are about to scan)
Then, Avast WILL STOP when it encounters a potential infection. Avast will not continue the scan unless you tell it to do so. Do not continue the scan until you fix the virus.
This can be done by selecting one of the options. If you recognize the file as a virus name such as Win32trojan or winbeagle etc, then delete or repair.
If the file name is NOT familiar, then MOVE it to the vault until you determine what the file is and if it is needed.
Continue this procedure until the computer is virus free.
Techie