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Article ID: 221254 - Last Review: October 20, 2013 - Revision: 2.2

This article was previously published under Q221254
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IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986  ( ) Description of the Microsoft Windows Registry


Dcpromo builds two log files (Dcpromoui.Log and Dcpromo.log) in the %SystemRoot%\Debug folder on Windows 2000-based servers. Both files are useful for troubleshooting problems with the promotion or demotion of Active Directory servers.

This article describes registry settings that control the log detail in the Dcpromoui.log file.


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.

The Dcpromoui.log file captures status information on the promotion or demotion of an Active Directory computer from start to finish, including the capture of user input for the role the server will play in the forest.

Logging detail in the Dcpromoui.log file is controlled by the DCPROMOUI setting. To increase or decrease the logging detail captured, set the bit mask for the DCPROMOUI registry entry using the bit mask definitions shown below. Modify the data value for the DCPROMOUI (REG_DWORD) value in the following registry key:
The DCPROMOUI value is a bit mask. The high word is a mask of logging levels:
   0x0002   Trace constructor and destructor calls
   0x0004   Trace AddRef and Release calls
   0x0008   Trace function entry and exit
   0x0010   Output trace messages
   0x0020   Output log header with build and time stamp
   0x0040   capture the call stack for each invocation of
            operator new (chk build only)
The low word is a mask of output options:
   0x0001   Output to file in the %SystemRoot%\Debug folder
   0x0002   Output to debugger (OutputDebugString)
To enable maximum logging detail to the %SystemRoot%\Debug\Dcpromoui.log file and debugger, set the DCPROMOUI bitmask to 0xFF0003. (Enter "FF0003" and not the leading "0x" characters.)

The current log mask setting can be displayed by searching for the "logging mask" string in the Dcpromoui.log file (typically the fourth line from the top of the file). A DCPROMOUI setting of 0xFF0003 is displayed as logging mask 00FF in the Dcpromoui.log file.

  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Datacenter Server
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