Running Avast Free beta 4 on Win10x64:
Was reviewing my event log and I noticed that Avast apparently had created a Service entry for "VBoxAswDrv", and the error was that the specififed file was not found.
The service file it wanted to start was supposed to be located in \Program Files\Avast Software\Avast\NG.
To resolve the issue I deleted the service entry from Windows since I don't even have an "NG" folder, let alone that particular service file.
/jim