I have web service on IIS 7 on Windows 2008.
This web service must dlls of .NET Framework 3.5 (I have error about System.Linq using when I try to browse the web site)

The only place I found where it is possible to change .NET Framework version is application pools management, but The only two options I have are: no management code and .NET Framework 2.
In add/remove programs I have .NET Framework 3.5 installed and event does to it repair and iisreset, but I still have only to options in application pools management.

Any ideas?

Thank you for ahead.

1 Answer 1


By default, Windows 7 and Windows Server 2008 comes with .net 2.0 and .net 3.5. Remember even though you have .net framework 3.5 the CLR version is 2.0. There is no CLR v3.5. You can always host .net 3.5 related applications on the server where your web.config file will be referencing the necessary namespaces.

From the article .NET Framework 3.5 Architecture

The architecture of the .NET Framework version 3.5 and 3.5 Service Pack 1 (SP1) builds upon the earlier versions of the .NET Framework.

An application uses the same assemblies regardless of whether it targets the .NET Framework version 2.0, 3.0, 3.5, or the Client Profile, and regardless of whether the assemblies have been updated on a user's computer. For example, an application that uses Windows Presentation Foundation (WPF) and targets the .NET Framework 3.0 uses the same instance of the mscorlib assembly as an application that uses Windows Forms and targets the .NET Framework 2.0.

  • Thank you for replay, I have read the article, but I still didn't understood what I shoult to do for nor to receive Error: "Linq is not in the System namespace"?
    – Rodnower
    Apr 6, 2010 at 15:34
  • you will need System.Core reference Apr 6, 2010 at 15:43
  • using System.Core?
    – Rodnower
    Apr 6, 2010 at 18:53
  • check this out forums.asp.net/t/1264863.aspx Apr 6, 2010 at 18:55
  • corrected.. thanx Jun 25, 2010 at 6:27

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