The W3wp.exe process may intermittently stop responding, and event ID 1000 is logged in Exchange Server 2007 Service Pack 1

On a server that is running Microsoft Exchange Server 2007 Service Pack 1 (SP1) Client Access Server (CAS), the W3wp.exe process may intermittently stop responding.

Additionally, the following event is logged in the Application log:

Event Type: Error
Event Source: Application Error
Event Category: (100)
Event ID: 1000
Description:
Faulting application w3wp.exe, version version number, faulting module exprox.dll, version version number, fault address address.

Note When this problem occurs, you cannot access network resources through this CAS server from a client computer.

Update information

To resolve this problem, install Update Rollup 3 for Exchange Server 2007 Service Pack 1 (SP1) on the server.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.