Where to find “Microsoft.VisualStudio.TestTools.UnitTesting” missing dll?

Question

I am getting following error in my C# visual studio project:

The type or namespace name \'VisualStudio\' does not exist in the namespace \'Microsoft\'

Answer 1

The DLL you're looking for that contains that namespace is

Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll

Note that unit testing cannot be used in Visual Studio Express.