After you install Office 2000, you may notice files whose name begins with "fff" appearing in your Windows folder. For example, the file name may be similar to "fffeeecf_{44BE8B61-235B-11D2-8E66-D59A4E66D32D}.tmp". Also, every time you restart your computer, two more files beginning with "fff" appear in your Windows folder.

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When you install the Microsoft Script Editor, a program called Mdm.exe (Machine Debug Manager, which is used to provide application debugging) is also installed. Mdm.exe creates these files in your Windows folder.

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WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.


To work around this issue, remove Mdm.exe to be started as a service on Window 95 and Windows 98 platforms. To do this, remove Mdm.exe from the list under the following registry key: After all running instances of Mdm.exe are ended and no longer listed within Task Manager, you can delete any of the TMP files from the root of the Windows directory without affecting either the Microsoft Script Editor or Mdm.exe. The effect of taking this step is that remote debugging is disabled, provided that an instance of Mdm.exe is not started at the time an error is encountered. However, if another application reinstalls Mdm.exe, or if Mdm.exe /Regserver is run on a computer that is running Window 95 or Windows 98, Mdm.exe is re-added to the RunServices registry key (see above for full path).

NOTE: Running the Detect and Repair feature within Office 2000 causes Mdm.exe to be re-registered on the system.

Additionally, if the system has Internet Explorer version 5 or later, Mdm.exe can still be configured to start at the startup of Window 95 or Windows 98, if the script debugging feature in Internet Explorer is turned on. You can turn off this feature within Internet Explorer. On the Tools menu, click Internet Options. On the Advanced tab under Setting, make sure that Disable script debugging is selected.

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When Mdm.exe is registered on the Windows 95 or Windows 98 platform, the HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices registry key is modified to include Mdm.exe to start as a "service".

Windows 95 or Windows 98 starts each application listed under this key when Windows starts. This is done because DCOM on Windows 95 and Windows 98 does not support remote starting of DCOM components, which include Mdm.exe, although the implementation of DCOM on the Windows 95 or Windows 98 platform does permit connections to running objects. Therefore, upon installation, Mdm.exe registers itself to start each time Windows is started to enable the option of remote debugging with Mdm.exe.

Due to the way DCOM is implemented on the Windows 95 and Windows 98 platforms, Mdm.exe creates temporary files in the Windows folder that DCOM uses for access and decline of user rights to the DCOM component. Typically, DCOM calls Mdm.exe for startup as a proxy for another application that requires debugging support. Upon the shutdown of this application, a call is made through DCOM to shut down the registered DCOM server and, on Windows 95 or Windows 98, clean up any temporary files created by Mdm.exe. Because Windows 95 or Windows 98 is starting Mdm.exe directly as a program and not as a DCOM server, no registration is performed in DCOM. Therefore, on the shutdown of Windows 95 or Windows 98, DCOM is not aware that the Mdm.exe program needs to be shut down and the TMP files created are in need of clean up. Because DCOM does not perform cleanup, the temporary files remain after shutdown, and Mdm.exe creates a new set of TMP files every time Windows 95 or Windows 98 is restarted.

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For additional information about DCOM security, refer to Chapter 11, titled "Security", in Inside Distributed COM (ISBN 1-57231-849-X) or miscellaneous MSDN topics on the IAccessControl interface.

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