Correction - it was not message from me, but a reply to me. I don't know about this technique and haven't tried it.

>I saw it from Message #622328 of Nadya Nosonovsky (USA)and It it works very well.
>
>This goes in the program that launch your application:
>

>=myInstance('smvfp.exe')

>&& maybe the first line
>
>then, place this code at the bottom of the launch application:
>*********************

>Procedure myInstance
>Parameter myApp
>=Ddesetoption("SAFETY",.F.)
>ichannel=Ddeinitiate(myApp,"ZOOM")
>if ichannel =>0
>   wait window 'Your program is already running. This will finish' timeout 5
>   Ddeterminate(ichannel)
>   quit
>endif
>=Ddesetservice(myApp,"define")
>=Ddesetservice(myApp,"execute")
>=Ddesettopic(myApp,"ddezoom")
>return
>*******
>Procedure ddezoom
>Parameter ichannel,saction,sitem,sdata,sformat,istatus
>Zoom window screen Norm
>return
>*********

>
>This code works for VFP6 and VFP7.