You can do this, if you use the remote debugging protocol on the application command line  ...uniface.exe ... /deb=tcp:localhost+13020:nowait .... Then you start the debugger using the command line when you need it.  ...udbg.exe /deb=tcp:localhost+13020:create (You can use other ports instead of 13020 for different applications/shortcuts) This debugger can then be closed without affecting the application.  Downsides. If you have more than one copy of the application running at any one time, then you cannot choose which process gets debugged. 

Hi Uriel, When debugging in the "normal" way you can't. You can only do it with the remote debugging as Ian explained. Theo

Thanks you guys.