Dcdiag Overview

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Tool Location

The Dcdiag command-line tool is included when you install Windows Server 2003 Support Tools from the product CD or from the Microsoft Download Center (https://go.microsoft.com/fwlink/?LinkId=100114). For more information about how to install Windows Support Tools, see Install Windows Support Tools (https://go.microsoft.com/fwlink/?LinkId=62270).

Dcdiag.exe: Domain Controller Diagnostic Tool

This command-line tool analyzes the state of domain controllers in a forest or enterprise and reports any problems to assist in troubleshooting. As an end-user reporting program, Dcdiag encapsulates detailed knowledge of how to identify abnormal behavior in the system. Dcdiag displays command output at the command line.

Dcdiag consists of a framework for executing tests and a series of tests to verify different functional areas of the system. This framework selects which domain controllers are tested according to scope directives from the user, such as enterprise, site, or single server.

Corresponding UI

There is no corresponding user interface (UI) for this tool.


All domain controllers in the same domain are peers of one another and any domain controller can make directory updates.

However, given the way in which directory updates are replicated from one domain controller to another, it is possible that difficulties can arise. For example, if the necessary domain controllers are not connected by a replication topology, the appropriate domain controllers do not receive directory updates when replication occurs.

Also, in order for the (Domain Controller) Locator to find a domain controller, it must have accurate information so that it can properly locate the resource. If a domain controller is incorrectly advertised, the Locator is unable to find it.

System Requirements

The following are the system requirements for DCDiag:

  • Windows Server 2003 or Windows XP Professional


The version of Dcdiag that ships with Windows Server 2003 Service Pack 1 (SP1) is enhanced with a new replication security test (CheckSecurityError). You can run the enhanced version of Dcdiag on computers running Windows Server 2003 with no service pack installed and on computers running Windows XP Professional. However, to run the new replication security test (dcdiag /test:CheckSecurityError), you must run Dcdiag on a domain controller running Windows Server 2003 with SP1.

File Required

  • Dcdiag.exe

See Also


Dcdiag Remarks Dcdiag Syntax Dcdiag Examples Alphabetical List of Tools Spcheck Overview Nltest Overview Netdom Overview Netdiag Overview Netcap Overview Httpcfg Overview Dnslint Overview Dnscmd Overview Dhcploc Overview Dcdiag Overview Browstat Overview