What version of access are you using? I have had Access XP suddenly not show objects, but they do come back. I am not sure what causes it. In Access 2000 access seems to lose objects some times, but it is only an object at a time. When one tries to open an object it will open the next object instead. It is weird, to fix that you have to re-create the database, so mitch is headed the right direction. You will probably have to re-create the database so that your system tables get created properly.