When you register a window class, using the RegisterClass function, you can assign it a default cursor, known as the class cursor. After the application registers the window class, each window of that class will have the specified class cursor.
To override the class cursor, process the WM_SETCURSOR message. You can also replace a class cursor by using the SetClassLong function. This function changes the default window settings for all windows of a given class. For more information, see Window Classes.