Microsoft.Win32 (system.dll)delegate

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);

Associated Events

SystemEvents.UserPreferenceChanged( )

    Part II: Programming with the .NET Framework
    Part IV: API Quick Reference
    Chapter 26. System