You can do it right at app startup time:

with _screen
   .Top = -10000
   .Left = -10000
   .Height = 100
   .Width = 100
endwith

* rest of the app goes here

But you may not need to do this until somewhere in your app shutdown code, because there will be a button on the task bar for VFP is _screen.visible = .t. which you may not want for the whole duration of the app which I assume is running as a TopLevel form.

>If i leave the screen visible; where can i modify the coodinates(left & top ) of the screen if i don't want to see the screen {flashing} at startup ?