If the enable state of hwnd is changing, a WM_ENABLE message is sent before this function returns.

If a window is disabled, its child windows are also disabled, although they are not sent the WM_ENABLE message. Typically, a window changes appearance when disabled. For example, a disabled push button is displayed with half-tone text.

If hwnd is disabled, and it, or one of its descendants, is the focus window, that window loses the focus, so that no window has the focus. However, a disabled window may subsequently be assigned the focus, in which case it should respond to keyboard input.