In addition to Albert's comments, you could simply apply a password to
protect the VBA project. It doesn't prevent the user from getting to the VBE
screen, but it prevents them from seeing, changing or adding code to the
file (in other words, even if they get to the VBE, they can't do anything
there).
In VBE: Tools> (Your project) Properties> "Lock for Viewing" and "Password
to View"
Password crackers are out there, so this is just a roadblock for people who
might know "just enough to be dangerous" but not truly serious hackers.
As far as disabling F11 goes:
In the Access User Interface: Tools>Startup: uncheck "Use Access Special
Keys". This disables Alt-F11 and other Special keys. It also prevents
breakpoints you set from actually breaking (since that acts like alt-F11),
so don't forget you've turned them off if you are debugging
. However,
unless you have disabled the Shift-Bypass, this setting can be changed back
at will. You would also have to alter your Menus to remove the VBE option
(Tools>Macro>VBE), as well as lock-up the menus to prevent a user from
re-adding the VBE option via Customize. Also prevent Users from getting to
the Database window so they can't open a code module in Design view...
If this is a "casual" app, it's much easier to simply apply a password to
the code project and not sweat users getting to the VBE
HTH,