The Microsoft Windows operating environment identifies each form in an application by assigning it a handle, or hWnd. The hWnd property is used with Windows API calls. Many Windows operating environment functions require the hWnd of the active window as an argument.

The handle returned by the hWnd property is assigned to the form at run time. Therefore, the handle might be a different value every time the form runs, but the value remains constant during the life of the form. If the same form runs multiple times, each instance of the form can have a different hWnd value.

hWnd is available in user-defined Forms and Toolbar objects and is read-only at both run and design-time.