You could Make an .ACCDE, and give that to your users to execute.
You can create an .accde file from an
.accdb file by clicking Database Tools
on the Office Fluent Ribbon, and then
clicking Make ACCDE. When you create
an .accde file, Access compiles all
the code in the database and strips
the editable version of the code from
the new .accde file. This process both
reduces the size of the resulting
database and guarantees that no one
can change the original source code.
When you open an .accde file in
Access, the form and report designers
and the Visual Basic Editor are not
available. In addition, you cannot
transfer forms, reports, and modules
to another database by export or
import.
However, since an ACCDE is apparently less secure than its predecessor the MDE, your best bet might be to convert the database to Access 2003 format by using the Save As command, and making an MDE from that. If you open an older .mdb file in Access 2007, a Make MDE command appears on the Database Tools tab instead of the Make ACCDE command that appears when you are working in an Access 2007 database.