Outlook Express Fails LDAP Connections Over Slow Links

ID: q193498

The information in this article applies to:


When attempting to establish a Lightweight Directory Access Protocol (LDAP) connection, the connection may fail or time out.


This problem can occur because the Wab32.dll file has a hard coded 10-second timeout limit for establishing LDAP connections. This value is insufficient for some cases, particularly if slow links are involved.


To resolve this problem, obtain and install Internet Explorer 4.01 Service Pack 2. You can obtain Internet Explorer 4.01 Service Pack 2 from the following Microsoft Web site:



Microsoft has confirmed this to be a problem in Microsoft Internet Explorer version 4.0 and Microsoft Outlook Express.


With the hotfix installed, the timeout value of 10 seconds is no longer hard coded in Wab32.dll. Instead, the Windows Address Book (WAB) reads the timeout value from the following registry location:

   "LDAP Connection Timeout"=DWORD:10

If this registry key and value do not exist, WAB creates it at run-time, and populates it with a default value of 10 seconds.

Additional query words: time

Keywords          : kbenv kbnetwork msiew95 outex 
Platform          : WINDOWS
Issue type        : kbprb

Last Reviewed: April 2, 1999