I can't seem to open any of the screen files with screen 4.  Every time I try to open a file (1024.set) I get an error message (blank box with exclamation point in tringle).  If I click OK, the computer just beeps and won't do anything, so I have to ctrl-alt-del and forcibly end screen4.  Does anyone know what I'm doing wrong?

Default>Mach Location

You need to tell Screen4 where Mach3 is installed.

Thanks!! that was it.