Why isn't my machine.config HttpModule running in my web app?

Question

I wrote a HttpModule in .NET 3.5, 32 bit Win 2003, IIS 6 that worked great. Its assemblies were in the GAC and the config was in the machine.config. Everything has been great for years.

I just brought it all over to a new .NET 2-4, 64 bit Win 2008 R2, IIS 7.5 machine and put the same, old configuration in the machine.config. Unfortunately, the module isn't listed as those that are running on the site. When I put the configuration directly into a site's web.config, then it runs as expected. Why isn't my app inheriting the HttpModule from the machine.config?

This config does nothing in the machine.config, but works as expected in the web.config.

<system.webServer>
    <modules runAllManagedModulesForAllRequests="true">
        <add name="MyModule" type="MyModule, MyAssmebly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=abcdefghijklmno" />
    </modules>
</system.webServer>

I put the config in every possible machine.config file to no avail:

• C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config
• C:\Windows\Microsoft.NET\Framework64\v2.0.50727\CONFIG
• C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config
• C:\Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG

UPDATE

Other elements of the configuration are inherited to the web.config: system.web\compilation and system.serviceModel\bindings to name a couple. The module uses WCF that is configured in machine.config. It appears to just be the HttpModule that isnt being inherited. No, there is no <clear/> anywhere.

Answer 1

Apparently, the machine.config is not responsible for defining the system.webServer section. In fact, it defines the section as

<section name="system.webServer" type="System.Configuration.IgnoreSection, System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>

Note the type: System.Configuration.IgnoreSection.

The system.webServer section is defined in

%windir%\system32\inetsrv\config\applicationhost.config

Directly after the system.webserver section, there is

<location path="" overrideMode="Allow">
    <system.webServer>

    <modules>
        <!-- add the module here -->
        <add name="MyModule" type="MyNamespace.MyModule, MyAssmebly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=abcdefhijklmnop"/>

    </modules>

    </system.webServer>

</location>