A couple of possibilities:
1. By using Access's user-level security and setting the relevant user permissions to the object.
2. By preventing users from getting to the DB window, and creating two forms - frmPassword and frmMain. Force the users to enter a password into frmPassword, which is validated against a table or constant, before opening frmMain which allows updates to your table.
Ed Metcalfe.
Please do not feed the trolls.....