When you apply security to a database and you've joined
that workgroup, the login dialog box will appear even if
you are opening an unsecured database. If you enter your
user name and password (of your secured database) your
unsecured database will open. However, if you don't want
your unsecured databases to prompt for a login, you can
create a shortcut to your secured database that includes
the path to the .mdw file. See "Startup command-line
options" in the Access online help system for the
required switches. Then you will need to join the
system.mdw that was installed with Access. It lives in
different places, depending on your operating system.
Hopefully, you didn't modify the original system.mdw
file. If you did, COPY IT SOMEWHERE ELSE and restore the
original system.mdw file from another client or reinstall
Access. Make sure your shortcut points to the .mdw file
that contains your security. In addition, I second the
advice from Scott McDaniel. I always keep a backup copy
of my .mdw file in case something goes wrong!