I have a Shell Namespace Extension C++ COM DLL that must have both a 32 bit and 64 bit version installed on a 64 bit machine, because when 32 bit applications perform a file-> open the dialog that is presented is a 32 bit shell. The problem is that both my 32 bit and 64 bit COM objects have the same progid and the VS setup project will throw an error when including two files with the same progid. How do I get around this issue if I want to maintain the same code for both 32 and 64 bit? Currently I just have two different MSI's (32 and 64) and they both must be ran on the 64 bit machine.