The ExitCode property specifies a Win32 error code defining any problems encountered in starting or stopping the service. ...

The ExitCode property specifies a Win32 error code defining any problems encountered in starting or stopping the service. This property is set to ERROR_SERVICE_SPECIFIC_ERROR (1066) when the error is unique to the service represented by this class, and information about the error is available in the ServiceSpecificExitCode member. The service sets this value to NO_ERROR when running, and again upon normal termination.