Try the command-line scanner? You can use the AVGSCAN.EXE file.
It has to be run with parameters, so if you want to scan your C:\ drive, you have to run this command-line scan in the following format.
AVGSCAN.EXE C: /parameters.
If you want to scan a specific file/directory, you have to replace the C: path by specific path. The list of possible parameter you can get by the AVGSCAN.EXE /? command.
Or go to the following for a PDF Reference Guide of AVG.