Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether it has been changed from its default value:


If the Exchange Server Analyzer finds that the value of TopoRecheckSecs is not equal to the default value of 900 seconds, a non-default configuration message is displayed. The Exchange Server Analyzer reports this configuration for informational purposes only. No action is required.Because DSAccess uses the value of the TopoRecheckSecs registry value to set the interval at which the global catalog list is rebuilt, an incorrect setting can cause a decrease in performance. Best practice is to use default configuration settings for Exchange Server whenever possible. However, if this registry value is present, it may have been added and configured on the recommendation of Microsoft Product Support Services to correct an issue that arose previously. You should consider removing this registry value unless it was added and configured on the recommendation of Microsoft PSS or other expert guidance.

This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.
To delete the TopoRecheckSecs registry key
  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeDSAccess

  3. In the right pane, locate and delete the TopoRecheckSecs value.

  4. Close the registry editor.

  5. To make this change permanent, restart System Attendant.

Before you edit the registry, and for information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (

For more information about optimizing global catalog placement for Exchange Server, see Understanding and Troubleshooting Directory Access (