DOCUMENT:Q163166  19-APR-2000  [iis]
TITLE   :HOWTO: Fixing the "500 Extended Server Error" Problem on ISAPI
PRODUCT :Internet Information Server
PROD/VER:winnt:1.0,2.0,3.0,4.0,5.0
OPER/SYS:
KEYWORDS:kbiis300 kbiis400 kbiis500

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The information in this article applies to:

 - Microsoft Internet Information Server versions 1.0, 2.0, 3.0, 4.0, 5.0 
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SUMMARY
=======

This article explains how to fix the following Microsoft Internet Information
Server (IIS) error:

   500 Server Error. Specified Module could not be found

MORE INFORMATION
================

When a Web browser (such as Internet Explorer 3.0) invokes an ISAPI DLL on the
IIS, the server may display the above error message. The reason for this error
is that one or more DLLs on which the ISAPI DLL directly or transitively depends
is either not installed on the IIS server or the DLLs are located in a directory
that IIS does not search. If this is the case, IIS sends back to the browser an
HTTP status code 500, which the browser then displays as the above error message
instead of the expected output from the ISAPI DLL.

To fix this situation, copy all the DLLs on which your ISAPI DLL directly or
transitively depends to the System32 directory of the IIS server.

A very common cause for this problem is building an ISAPI DLL using the ISAPI
Wizard in Visual C++, using the share libraries option, and then not having the
Visual C++ and MFC runtime DLLs installed on the IIS server. The Visual C++ and
MFC runtime DLLs typically needed are the following.

For Visual C++ 4.2 Debug:

 - Msvcrtd.dll
 - Mfc42d.dll

For Visual C++ 4.2 Release:

 - Msvcrt.dll
 - Mfc42.dll

For Visual C++ 4.1 Debug:

 - Msvcrtd.dll
 - Mfc41d.dll

For Visual C++ 4.1 Release:

 - Msvcrt.dll
 - Mfc41.dll

To generically determine which DLLs you need to install on your IIS server, use
either the DUMPBIN utility that ships with Visual C++ (use the /imports option),
or the Quick View facility of Windows Explorer (if it is installed) to view what
DLLs your ISAPI DLL depends on. Either program provides you with a list of
dependent DLLs. Remember you may need to repeat this process for any DLLs listed
to determine transitive DLL dependencies.

REFERENCES
==========

For additional information, please see the following article in the Microsoft
Knowledge Base:

   Q135338 How To View Exported Functions in a DLL.

(c) Microsoft Corporation 1997, All Rights Reserved. Contributions by Leon
Braginski, Microsoft Corporation


Additional query words:

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Keywords          : kbiis300 kbiis400 kbiis500 
Technology        : kbiisSearch kbiis500 kbiis400 kbiis300 kbiis200 kbiis100
Version           : winnt:1.0,2.0,3.0,4.0,5.0
Issue type        : kbhowto

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