To use a control window in a dialog window, an application specifies the control in a dialog template in the application's resource-definition file. A dialog template typically includes several control windows. When the application loads the dialog-template resource and displays the dialog window, the system automatically displays the control windows as part of the dialog window.

An application can send messages, through the dialog-window procedure, to a control window to change its state. The control window sends notification messages to the dialog-window procedure. The content of a notification message depends on the type of control window.