Make sure that you are opening an MDB type file and not an MDE file.  If the
user converted the database to an MDE file all design capabilities (except
for Tables and Queries, IIRC) are removed.  You will need your backup copy
of the database.  You do have one, right?

If you are working with an MDB, perhaps the user did not disable all the
settings:  Try holding down the shift key while opening the database to
bypass startup code.  If the database opens but does not display the
Database Window, then press F11.

For the future, consider deploying your database(s) as follows (some may
call it CYA, but I like to think of it as protecting a company's assets and
avoiding unwarranted expense of recreating destroyed work):

1.  Split your application into a Front-End (FE), containing all Queries,
Forms, Reports, Macros and Modules and a Back-End (BE) containing all shared
tables.   The BE is stored on the server and a copy of the FE is distributed
to each user's hard drive.  The FE uses linked tables to link to the BE.

2.  Keep a copy of the current FE database on the server, where it will be
backed up in accordance with your network backup policies/procedures *and*
where it will be available for re-copying to a user's hard drive when the
user has damaged their copy.  Do NOT do development work on this copy.

3.  Keep a copy of the current FE database on your own computer.  This is
the copy you would do your development, modifications, etc., on.   When you
complete any nods and are satisfied with them, you can copy a New Current FE
to the network and from there distribute to each user.

--
Cheryl Fischer
Law/Sys Associates
Houston, TX