I wonder if I can just copy/paste the RB.exe file without going through a full installation? hmmmm.... I might have to test that theory.
update:
I went even farther than copying/pasting the RB executable. I copied the whole RealBand directory, thinking that would provide everything I need to run RB.
And in a way, that worked. RB did start. But the startup process included a number of messages along the lines of "Oh no! RB can't find the BB directory! Danger Will Robinson! We really need some stuff in that directory, but we can't find it! You must not have installed correctly!"
After clearing multiple such warnings, the program started. But, when I tried to put effects on a track, there were none to be found. Apparently those are shared between programs, and they get stored in the BB folder. There might be more things that get shared, but I pulled up the brakes at this point.
I probably could have copied the effects to a sham bb directory, but I'll wait for Power Tracks to be released in 64 bits