Detemine If EXE Is X64 Or X86?

I am writing a utility that converts an application on a system to another version without the need to re-install. However the action is dependent on whether or not the existing installation on the machine is either x64 or x86.

In researching online through the many VB.NET pages I keep finding "How to determine if my EXE is x64" but this is not what I am looking for. I am looking to find whether or not an executable is compiled 64bit or 32bit.

In this directory there is also a collection of DLLs that may assist in determining this. If checking an executable is not possible.Additionally, in the event that anyone asks, determining if the OS is x64 or x86 does not help. It needs the be the files directly.