While using the Fakes (Moles) isolation framework, you will notice some mscorlib shims are missing, particularly in the System namespace. For example, System.Fakes.ShimEnvironment does not exist. Although these are missing by default, you can request the compiler to generate shims for specific objects. This post provides steps to request Fakes shim generation for System.Environment and an example of implementation.
This tutorial targets Microsoft Fakes Isolation Framework on Visual Studio 2012 Ultimate or later; but, this process is also compatible with the developmental version, project name "Moles", running on Visual Studio 2008 or 2010. This tutorial assumes you have basic understanding of the MSTest framework.