System.mdw is the default Workgroup file created by Access. Normally, if it
is deleted Access will simply recreate it upon opening. This may not happen
if the install was customized to define a workgroup file. If so, you may
need to ask the person who customized the install.
Depending on your version of Access and Windows, the file should be located
in "%userprofile%\Application Data\Microsoft\Access", "%windir%\System", or
"%windir%\System32".
You may want to check these locations for a System.mdw file (the first
location would apply to a WinNT, 2k, XP computer running Access 2000 or
newer). If the file is there, it may be corrupted. If so, close Access,
rename the file to System.mdw.old, then reopen Access and open a new
database. The System.mdw file should be recreated.
It is also possible that someone created their own, customized workgroup
file to apply Access Security and they named it System.mdw instead of giving
it a unique name. If so, you'll have to ask the person who secured the
database where you can find the workgroup file.
