>> How it is easy to find a descriptor HWND of windows?
>
>I wanted a descriptor HWND of Forms in VFP.

Check George Tasker's obj2bmp in files section. If you want main window handle then in foxtools.fll there is MainHwnd().
Also in VFP API lib check _WhToHwnd() and Windows API
GetWindowRect(mainhwnd, &Rect).
Cetin