http://office.microsoft.com/en-us/access/HA100678311033.aspxExtract from link.
Note You can use Office Access 2007 to open an earlier-version database that has been secured by using user-level security. However, user-level security does not exist in Office Access 2007 databases. There is no command on the Ribbon (part of the Microsoft Office Fluent user interface) to start the Workgroup Manager, but you can still start the Workgroup Manager in Office Access 2007 by using the DoCmd.RunCommand acCmdWorkgroupAdministrator command in VBA code, or by creating an Access macro that contains the RunCommand action with a Command argument of WorkgroupAdministrator.