This delegate defines the signature an
event handler must use to
receive the SystemEvents.UserPreferenceChanged
event. This event is raised when a user applies configuration
changes, usually through one of the setting modules in the Control
Panel. Note that not all changes raise this event, so it is best to
first test it to make sure it accomplishes everything you need before
you rely on it.
public delegate void UserPreferenceChangedEventHandler(object sender,
UserPreferenceChangedEventArgs e);
