On this screen you can specify how long the scan logs are kept before they are deleted and also the maximum size of the scan logs. This ensures that the space on your harddisk is optimized by limiting the size of the logs and removing logs which are no longer needed.
If the box “Enable debug logging” is checked, a special log file will be created if an error occurs while the program is running. If the error persists, this log can then be sent to avast! technical support and may help to identify the cause of the error.