When you first upgrade to Office 2007, one of the small "gotchas" in opening an older Access database is utility.mda.

Most Microsoft Access databases created in Office 2000, XP, and 2003 open and run just fine in Office 2007. Best to leave them in their original "mdb" format and run them in "compatibility" mode. Though compatibility mode sounds shabby, its not and to be preferred unless you specifically plan to use Office 2007 features in an all-2007 environment.

utility.mda is an older optional library of functions dating back to Office 97. Older databases may have carried forward references to it even though it has become obsolete with additional functionality directly in Access itself. With Office 2007, it may become a show stopper. You may get an error as soon as the database opens

The good news is that you can remove it with little chance of problems. Let the database open with the error message. Click "OK" and you will likely find yourself in the code debugger. If not, see below. Then,

1. Click Run -> Reset
2. Click Tools -> References. Find the reference to utility.mda and uncheck it. Click OK
3. Click Debug -> Compile {database} name.
If that was the only problem, you should get no further message.
4. Click File -> Close and Return to Access

You should be good to go.

If you didn't wind up in the code debugger window, then from the Access menu, click Database Tools -> Visual Basic and now you should see the code debugger and proceed as above.

If step 3 doesn't work, you may have other older libraries that need to be cleared up, and may need additional assistance with them.