It is not even possible to open an Access database without some workgroup
file. If you properly, and completely, secured the database and then
deleted the workgroup you may be in a world of hurt. I would suggest that
you get a copy of the original system.mdw that shipped with Access and see
if you can open it that way.
I had setup the WOrkgroup file, and then i reverted back,
just because i didn't know if that was the route i wanted
to take. Now i do not have change permissions on any of
my querys or forms.