Windows Explorer Scan
This is simply the facility to scan an individual file without opening the main program interface or without running a scan from the command-line.
To scan an individual file, just right-click the file to open the context menu and select the option “Scan <filename>”.
To add this scan to the list of pre-defined scans on the Scan Now page, go to the program “Settings” and check the box “Show special scans in avast! user interface”. You will then be able to access and adjust the scan parameters as required.