Change .NET Framework version of application pool to 3.5?

Question

I've installed .NET Framework 3.5 SP1 on web server (Server 2008 Enterprise), so running IIS 7.0.

I want to change the version of .NET Framework used by an existing site. So I right-click on appropriate Application Pool and selected Edit Application Pool. The .NET Framework dropdown does not include an explicit entry for framework 3.5, but just 2.0.50727.

Does anyone know off the top of their head--is this just because the version of the core RTL in 3.5 is still 2.0? Or do I need to do something additional to get IIS to see version 3.5? (Did try restarting IIS).

Thanks!

Answer 1

Does anyone know off the top of their head--is this just because the version of the core RTL in 3.5 is still 2.0?

YES

Answer 2

You do not need to do anything more, other than have a properly configured web.config

Answer 3

The dropdown in question is using version of the CLR loaded into your application pool's process space, which must be unique (you can't load a 1.1 CLR into a process with an already loaded 2.0 CLR, and vice versa).

However, .NET 3.5 uses the v2.0 CLR - the only thing added are new versions of libraries and some compiler support around the new features in VB.NET and C#. If you select 3.5 you'll be using 3.5 as long as your assemblies reference 3.5 versions of assemblies.

Answer 4

The 3.5 framework still runs on top of the 2.0 CLR so what you are seeing is correct.

Scott Hanselman has a nice post about the details of this:

Answer 5

We just installed the 3.5 framework on our server (Windows Server 2003 /IIS6), rebooted, and that was it.

Of course, you have to have applications developed against version 3.5 of the framework, but it isn't like the change from 1.1 to 2.0, where you need to change the .Net settings in your web site properties using IIS Manager.

Answer 6

root file is missing occurred when i copy my project and run on another computer then A ERROR comes ..... Root element is missing.

Source Error:

[No relevant source lines] c:..minorproject\web configfile