I have a related file that is opened when needed and is minimized upon startup. How do I prevent users from accessing it without having to put a password for that file?

If you want to restrict users from seeing the contents of the file at all, upon opening, run a script that:

1. Hides and locks the status area;

2. Goes to a layout with no fields, no buttons, no nothing (except maybe text saying "Restricted Access").

You'll also need to prevent the average user from modifying layouts and scripts so that they cannot get to restricted layouts via either of these methods. You can do both these things in the Access Privileges dialog.

HTH

Jerry