IIS7 deployment - duplicate 'system.web.extensions/scripting/scriptResourceHandler' section

Question

On attempting to deploy a .net 3.5 website on the default app pool in IIS7 having the framework section set to 4.0, I get the following error.

There i

Answer 1

I've solved it, doing the following steps:

1. I created a new application's group in IIS.
2. Open advanced settings for the site or web application that is having this problem.
3. And set the new application's group.

Here you have the images of these steps: