Maybe one of subdirectories doesn't exists on the user PC?

>The following line works fine on my development PC but causes an error when the application is installed on a users PC.
>
>modi comm "c:\program files\freemansoftware\tip\fedcodes.txt"
>
>The error is an invalid path or filename. I can't for the life of me figure out what's wrong.
>
>Any help?