Missing "Machine Key" in IIS manager

A number of guides on setting the ASP.NET machineKey via the IIS manager tell me to open up the "Machine Key" section in the Feature View, for example:

My IIS install doesn't have this icon. How do I add it? I've had a good look through the "Add Role Services" but didn't find anything that seemed relevant.

Here's what the list looks like on my server when I select the machine in the list on the left:

Solution 1:

I had to go to 'Turn windows features on or off' in Control Panel -> Programs and Features, and enable ASP .NET under World Wide Web Services.

Check the checkbox for Internet Information Services -> World Wide Web Services -> Application Development Features -> ASP.NET.

Solution 2:

The first thing to check is the configuration file for the IIS Manager at:

%systemroot%\System32\inetsrv\config\administration.config

Under the moduleProviders node in the ASP.NET Modules section there should be an entry like this:

   <add name="MachineKey" type="Microsoft.Web.Management.AspNet.MachineKey.MachineKeyModuleProvider, Microsoft.Web.Management.Aspnet, Version=8.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />

The version number may be 8.0.0.0, 7.5.0.0 or 7.0.0.0 depending on your OS.

If that's there, you can look at the actual file providing this feature, in the case of 2008 R2 it is at:

C:\Windows\assembly\GAC_MSIL\Microsoft.Web.Management.Aspnet\7.5.0.0__31bf3856ad364e35\Microsoft.Web.Management.Aspnet.dll

If that's always there, I would start up Process Monitor and filter for

Path  contains  Microsoft.Web.Management.Aspnet.dll

than start IIS manager and review the Result column in Process Monitor, you should get a bunch of entries with Success, Buffer Overflow and File Locked with only readers

I really have no idea why the icon is not showing up on your system, but that's how I would look for a problem.