The options in the Tools/Startup dialog box should get you what you want. Uncheck all options and specify your form as the startup form and when you open the database you will see nothing but your form and a basic menu at the top. If you want to remove even that menu, you can create a custom menu (with nothing in it but an Exit option) and specify that menu in the startup options.
While this does work to produce the results you describe as what you want, you need to know that if the user knows to hold down the shift key when opening the database, they will again have all of the normal options available to them.
If you really want to have your application to the point that the user cannot have other options to work with, look into creating an mde type file and have your users use the mde file and not an mdb file.