Topic Last Modified: 2007-08-28

The Microsoft® Exchange Server Analyzer Tool queries the CIM_Datafile Microsoft Windows® Management Instrumentation (WMI) class to determine whether a file named ALockout.dll is present in the System32 folder on the Exchange server. ALockout.dll is part of the Account Lockout and Management Tools (ALTools.exe). These tools help administrators manage accounts and troubleshoot problems with account lockout.

If the Exchange Server Analyzer finds ALockout.dll present on an Exchange server, the Exchange Server Analyzer displays an error.

The Account Lockout and Management Tools should not be used on servers that host network applications or services, including Exchange servers. If the Account Lockout and Management Tools are installed on an Exchange server, they could prevent the Exchange services from starting. Therefore, it is strongly recommended that you uninstall the Account Lockout and Management Tools from this Exchange server.

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 correct this error
  1. At a command prompt, type regsvr32 /u alockout.dll.

  2. Delete the ALockout.dll value that is under the following registry key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows\AppInit_DLLs

After you delete the ALockout.dll value, the AppInit_DLLs registry entry is blank. Restart the computer.
  1. Delete the ALockout.dll file from the System32 folder.

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 the Account Lockout and Management Tools, see "Account Lockout Tools" in Account Passwords and Policies (