In case you need to find out (in IIS7) the version of ASP.net which your website is running, it’s very simple.

Open IIS (Start/Administrative Tools/Internet Information Services Manager). Double click on the server to open the node. Next, double click on ‘Application Pools’. This will give you a list of the Application Pools of websites running on that server. You should see the version of the .Net Framework for your site there.