Article ID: 285172 - View products that this article applies to.
This article was previously published under Q285172
NoticeThis article applies to Windows 2000. Support for Windows 2000 ends on July 13, 2010. The Windows 2000 End-of-Support Solution Center
(http://support.microsoft.com/?scid=http%3a%2f%2fsupport.microsoft.com%2fwin2000)is a starting point for planning your migration strategy from Windows 2000. For more information see the Microsoft Support Lifecycle Policy
This article discusses schema updates.
IMPORTANT: This article contains information about modifying the Active Directory schema. If problems occur, a system backup, or reinstallation of your system, may be the only way to recover data.
CAUTION: You should use extreme caution when you make any changes to the Active Directory schema because the changes occur forest-wide, and you cannot remove objects and attributes that are added to the schema.
The extension or the modification of the Active Directory schema requires write access to the schema. This is enabled by means of the "Schema Update Allowed" registry key. Schema updates may be enabled by means of the Schema Management Console, or directly in the registry. The schema updates can only be enabled on the domain controller that holds the schema master role.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/322756/ )How to back up and restore the registry in Windows
Schema updates may be enabled by means of the Schema Management Console or by editing the registry.
To Enable Schema Updates by Means of the Schema Management Console:
To Enable Schema Updates by Means of the Registry:It is not recommended to enable schema updates by directly editing the "Schema Update Allowed" registry key. Schema updates should be enabled through the console method, whenever possible. If for some reason the console method cannot be used, the following registry key may be edited directly:
To directly edit this registry key, perform the following steps:
More Information:Clicking to select the Schema may be modified on this Domain Controller check box in the console adds the "Schema Update Allowed" registry value if it is not present.
Clicking to clear the Schema may be modified on this Domain Controller check box sets the "Schema Update Allowed" registry value to zero, but it does not delete the value.
Further information about the Active Directory schema may be found in Chapter 4 of the Windows 2000 Server Distributed Systems Guide, which is part of the Windows 2000 Server Resource Kit.
Article ID: 285172 - Last Review: February 28, 2007 - Revision: 2.6