Q: What is a pop-up window?

A: A pop-up window is an overlapped window with optional title bar and border.
It is created by specifying WS_POPUP style in CreateWindow or CreateWindowEx function.

  • pop-up windows are generally used for dialogs and other temporary windows that appear outside an application's main window;
  • in practice is used the composite style WS_POPUPWINDOW instead of WS_POPUP;
    this adds a border and system menu.
    #define WS_POPUPWINDOW      (WS_POPUP          | \
                                 WS_BORDER         | \
  • to make the system menu visible, WS_POPUPWINDOW must be combined with WS_CAPTION.

See also