>I read all your messages about SDI forms without main VFP window
>but I try it in VFP 3.0 and it doesn't work.
>
>SCREEN=OFF in Config.FPW
>
>is not a solution for VFP 3.0
>
>Please help me!!!

SDI is applied for VFP5. You can hide VFP3 _SCREEN firing e.g. _screen.left=-2000 in first lines of your app, however you will still see it when you launch the app (the way to prevent it is to use 'Run Minimized' Windows shortcut).