It's basically a toast the 64 bit install and start over.
Yes, we all wish Microsoft had addressed this better.
Bob
My system is running a 64-bit version Of Vista v 6.0 and I have had problems not being able to run some software because there is no 64 bit version available. Can I switch (how?) to a 32 bit version? What are the pros and cons of the 2 versions?

Chowhound
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