Ollieollieollie,
Have you attempted to run the setup without compatibility mode? If not I would try that first. Moving from a 64-bit operating system to 32-bit will require a clean install as the two architectures are too drastically different to simply “downgrade.”
Also, should you require additional Microsoft does have an official Windows 7 Support Forum located here
http://tinyurl.com/9fhdl5. It is supported by product specialists as well as engineers and support teams. You may want to check the threads there for additional support.
Jessica
Microsoft Windows Client Team