How can I change the target-framework in Visual Studio 2010 (unit-Test)?

Question

I developed a small webpart. Now I want to create a unit-test for this webpart. I used this tutorial to create the unit-test. The presenter change the target framework from .Net 4.0 to 3.5, but I can´t change the target framework to 3.5 (I get the following information).

Microsoft Visual Studio: Attempted re-targeting of the project has been canceled. You cannot change the specified .NET framework version or profile for a test project.

So I tested this. Unhappily it doesn´t work.

as Information: If I want create a new test-Project Visual Studio doesn´t show any projects for .NET 3.5 (only 4.0).

How can I change the target framework to 3.5? Are there updates for Visual Studio 2010?

Thank you in advance!

Answer 1

Install Visual Studio Service Pack 1. I had this issue and this resolved it for me.