Windows 7 Enterprise, SP1
Created a shortcut to open MS Access 2003 that worked. Now that I have been upgraded to Windows 7 and Access 2010, I updated my shortcut. It's a long shortcut and I have shortened it below.
"C:\Program Files (x86)\Microsoft Office\Office14\MSACCESS.EXE" "C:\database.mdb" /WRKGRP "\\serverpath\filename.mdw"
The shortcut opens Access and I get the error message that Access could not find
UNC path was the problem. When I switched to the mapped drive letter, everything worked.
Also in installing it on another computer with a different mapping, when I used by mistake the wrong drive letter, again the error message changed .mdw to .mdw1.
By the way, this Microsoft Article: Set or change Access 2003 user-level security in Access 2010 - Access - Office.com
says you find the Security options on the Database Tools tab, Administer Group. In my installation, it is on the File tab, Info. That is also where you can find the User-level Security Wizard in Access 2010.