>My application has an external prg file that is used to execute a complex SET FILTER TO statement. I have a menu item to execute the prg as in DO SPECIAL_FILTERS. This works fine in the development environment, but in the runtime environment I get a 'file SPECIAL_FILTERS.PRG does not exist' error. This same error occurs if I include the full path to the file as in DO 'c:\program files\myapp\SPECIAL_FILTERS'. The file is definately there. Why can't the application see it?

The runtime cannot run .PRG only .FXP. If you create the program on the fly than you have to COMPILE it.