Creating a new application pool in IIS
If you see only two application pools and both of them are set to the .NET Framework 2.0, you have to install ASP.NET 4 in IIS: Open a command prompt window by right-clicking Command Prompt in the Windows Start menu and selecting Run as Administrator. Then run aspnet_regiis.exe to install ASP.NET 4 in IIS, using the following commands. (In 64-bit systems, replace "Framework" with "Framework64".) cd %windir%\Microsoft.NET\Framework\v4.0.30319 aspnet_regiis.exe –iru aspnet_regiis_installing_ASP.NET_4 This command creates new application pools for the .NET Framework 4, but the default application pool will still be set to 2.0. You'll be deploying an application that targets .NET 4 to that application pool, so you have to change the application pool to .NET 4. If you closed IIS Manager, run it again, expand the server node, and click Application Pools to display the Application Pools pane again. Content Copied from asp.net site. Details ca