Do you call ActivateOptions() when Threshold property is changed? Radovan Indeed I do ...
public static void LogToEventLog(bool logToEventLog) { if (_eventLogAppender == null) return; if (logToEventLog) { _eventLogAppender.Threshold = Level.All; } else { _eventLogAppender.Threshold = Level.Off; } _eventLogAppender.ActivateOptions(); } This is being shown in my console window: log4net: EventLogAppender: Changing event source [MyFirstApp] from log [Applicat ion] to log [log4net] log4net: EventLogAppender: Source [MyFirstApp] is registered to log [log4net]