Dear Thomas,
I’m sorry, but I’m not sure how to help. This archive is now quite old and I was not the one to originally provide it. Further discussion on MCRInstaller.exe is provided in the following forum topic; perhaps this discussion is useful for you: MCrunch (compiled version) - #2 by Jason.Jonkman?
Alternatively, you should be able to run a 32-bit application on 64-bit Windows. What error are you getting?
Best regards,