Why can't Windows 7 load the assembly PresentationFramework.Aero2?

Question

I recently finished my first WPF application I have been developing using Windows 8. It has worked fine on my machine. A friend of mine ran it in visual studio on his Windows 8

Answer 1

On a developer machine there are two versions of the presentation framework assemblies. Visual Studio references the "metadata only" version. When you deploy the assembly of the C:\Windows\Microsoft.NET\Framework\v4.0.30319\WPF folder it should work (see Problem with assembly PresentationFramework.Aero2)