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Fixing MMC errors

I’ve run into a number of issues with MMCs not working correctly or not working at all. Most of the time is has been caused by a corrupt MMC configuration file. All you have to do to fix this is delete or rename the old configuration file and the MMC will create a new one automatically.


The MMC configuration file is located in your Application Data folder and is associated with each User—not each computer.


Here is an example of the path to the config files:


\\server\share\UserSystem\username\Application Data\Microsoft\MMC (redirected App Data)

C:\Documents and Settings\mbroad\Application Data\Microsoft\MCC (local App Data)


Find the file that is appropriate for the MMC you are having issues with and delete or rename it. Most of the filenames are pretty obvious. Here are a few of them:



            GPMC             Group Policy

            DSA                Active Directory Users and Computers

            ADMGMT       Active Directory Management

            DSSITE           Active Directory Sites and Services


Here is the most common error you will see when you have a corrupt MMC:

MMC cannot open the file C:\WINDOWS\SYSTEM32\GPMC.MSC.


This may be because the file does not exist, is not an MMC console, or was created by a later version of MMC. This may also be because you do not have sufficient access rights to the file.