Asp.net 4.0 Handler Mappings Missing in IIS7

Thanks for your answer but I have already checked the root handlers which are the same as the application handlers and missing all the .net 4 ones.

Problem solved. All I had to do was to execute aspnet_regiis in %WinDir%\Microsoft.NET\Framework64\v4.0.30319

In IIS 8, we have to go to "Turn Windows feature ON and OFF" and got to "Internet Information Services > World Wide Web Services > Application Development Features" and select "ASP.Net 3.5, ASP.Net 4.5 and ISAPI Extensions and Filters"

It turns out that the root Server Node in IIS had all the appropriate handlers, but for some reason the web site in question (i.e. Default Web Site) did not have the handlers. I simply clicked Revert to Inherited in the right nav of IIS in the Handler Mappings section and all is working well now.

Don't forget to add the "-i" parameter!

C:\windows\system32>C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.
exe -i
Microsoft (R) ASP.NET RegIIS version 4.0.30319.17929
Administration utility to install and uninstall ASP.NET on the local machine.
Copyright (C) Microsoft Corporation.  All rights reserved.
Start installing ASP.NET (4.0.30319.17929).
.............
Finished installing ASP.NET (4.0.30319.17929).

C:\windows\system32>