I have the exact instructions for this on a CD at home. However, maybe the following will help (if not, I'll look it up):
Access instructs to export all objects from your own database into a new one, once users have been created and what-not. The point here is that the new database will be owned by the user who created it (which is the user currently logged into the old database from which you created the new one). If you are logged into your original database as the Admin user at that stage, then Admin will be the owner of the new database also (which defeats the point of creating it - this being in order to change the owner!).
If Admin is the owner of the new database, then you can't revoke Admin's permissions for database access. Since any user can log on as the Admin user, as long as they supply the password required by their local workgroup (which in the majority of cases is - nothing), then any user can access the database.
Solution (hopefully): once you've created the users in your original database and are at the stage when the new database is to be created (whether by wizard or manually), make sure you're logged on as a user OTHER THAN Admin, paying attention that the user you ARE logged on as has administrator privileges. Once you've created your new database, revoke administrator privileges from the Admin user (if you didn't do that before exporting) and explicitly revoke Admin's permissions to database access (under 'user and group permissions'). There is no reason to revoke Admin's permission to individual objects - denying access to the database as a whole will automatically deny access to any of its objects. This gets around the fact that you cannot delete the Admin user.
I think this should work (if done with the rest of the instructions!). If it doesn't, I'll look it up on a Cd-Rom I have and let you know the authorised Microsoft version of events.
(This caused me the same grief some time ago so I sympathise!)
Marko.
