This header is used by The Windows Shell. For more information, see:
scrnsave.h contains the following programming interfaces:
Provides default processing for any messages that a screen saver application does not process.
Registers any nonstandard window classes required by a screen saver's configuration dialog box.
Receives messages sent to a screen saver's configuration dialog box. A screen saver that allows user configuration must define this function.
Receives messages sent to the specified screen saver window.