To assign a specific .NET version to an application pool in IIS (Internet Information Services), you can follow these steps:
1. Open Internet Information Services (IIS) Manager: Go to the "Start" menu, search for "Internet Information Services (IIS) Manager," and click to open it.
2. Navigate to Application Pools: In the left-hand pane of IIS Manager, expand the server name, then click on "Application Pools."
3. Select the Application Pool: From the list of application pools, select the one to which you want to assign a .NET version.
4. Open Advanced Settings: Right-click on the selected application pool and choose "Advanced Settings" from the context menu.
5. Set the .NET Version: In the "Advanced Settings" dialog box, locate the ".NET CLR version" setting. It may be under the "General" or "Basic Settings" section.
6. Choose the .NET Version: Click on the drop-down list next to ".NET CLR version" and select the desired .NET version you want to assign to the application pool. Available options may include .NET Framework versions like v2.0, v4.0, or v4.5, depending on the installed versions on your server.
7. Save the Changes: Click "OK" to save the changes and close the "Advanced Settings" dialog box.
8. Restart the Application Pool (Optional): If you want the changes to take effect immediately, you can right-click on the application pool and choose "Recycle" from the context menu. This will restart the application pool and apply the new .NET version.
By assigning a specific .NET version to an application pool, you can ensure that the websites or applications running within that pool use the designated .NET runtime for executing their code. This allows you to have multiple application pools running different versions of .NET on the same IIS server.