HTTP 404 Error on Shtml.dll Using Forms on FrontPage Webs

When you try to use a FrontPage Search form or post to FrontPage discussion Webs through Proxy Server to a non-IIS Web server, an HTTP 404 error is returned pointing to Shtml.dll.

The problem occurs when the FrontPage Server Extensions are installed on the Proxy Server computer itself. The FrontPage installation adds a Filter DLL named Fpexedll.dll that is supposed to redirect CGI requests from legacy FrontPage versions to the new ISAPI FrontPage Server Extensions.

Although this file is necessary for users of FrontPage 1.x to author in IIS Web servers, it corrupts requests made through Proxy Server to CGI-based FrontPage Web sites.

Because the file Fpexedll.dll is designed for backward compatibility to FrontPage 1.x, it can be removed from the Proxy Server computer.

For IIS 4.0 and later versions:

1. Open the IIS snap-in in the MMC.
2. Right-click on the computer and select Properties.
3. Select the WWW Master Properties and click Edit.
4. Click the ISAPI Filters tab.
5. Highlight Fpexedll.dll and click Remove.
6. Click the OK button twice to close the properties dialog boxes.
7. Restart the World Wide Web Publishing Service.

For IIS 3.0 and earlier versions:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

1. Start Registry Editor (Regedt32.exe).
2. Locate the Filter DLLs value under the following key in the registry:

   HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/W3SVC
            /Parameters/Filter Dlls
          
   						

   NOTE: The above registry key is one path; it has been wrapped for readability.
3. Double-click the Filter DLLs key to edit it.
4. Delete the reference to the Fpexedll.dll file and, if necessary, the ; (semicolon) separator between it, and the next filter. For example, for FrontPage 98 the part of the string to delete is:
   C:\Program Files\Microsoft FrontPage\version3.0\bin\fpexedll.dll;
   Do not delete any references to other DLLs that may be present in this registry key.
5. Quit Registry Editor.
6. Restart the World Wide Web Publishing Service.

For more information on the Fpexedll.dll file, see the following Knowledge Base article: