Core Audio is not supported in microsoft xp OS on this code
MMDeviceEnumerator DevEnum = new MMDeviceEnumerator();
device = DevEnum.GetDefaultAudioEndpoint(DataFlow.Render, Role.Multimedia);
tbMaster.Value = (int)(device.AudioEndpointVolume.MasterVolumeLevelScalar * 100);
device.AudioEndpointVolume.OnVolumeNotification += new AudioEndpointVolumeNotificationDelegate(AudioEndpointVolume_OnVolumeNotification);