The folks at In Touch with Dynamics (GP) take us on a little trip with FRx Management Reporter migration Wizard and Office versions 64 bit v 32 bit. They do a great job explaining the ins and outs of 32 bit office vs. 64 bit office and how it relates to converting FRx to Management Reporter.
In Touch with Dynamics (GP): FRx Management Reporter migration Wizard and Office versions 64 bit v 32 bit
Archived post from 2011. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.