well, after much fiddling with the bootrec.exe... all of which was interesting and yielded strangely unexpected start up results... i followed coldsleep's advice on the virtual xp mode. yow! great! perfect! excellent!
this was indeed the most painless path possible and yielded the best (only) functional result.
initially i was wary of the xp mode because of some language on the windows download site that seemed to suggest that i'd have to let microsoft install some form of spyware onto the machine in order to use the update (am i just paranoid?)... but then found that the download didn't require that. so, i did it.
other options (and various brains consulted) suggested things like reinstalling the entire system beginning with xp instead of beginning with 7.... etc., etc.
all "pain in the butt" and time intensive solutions.
the xp mode works great.
the install from disc through the virtual xp window worked perfectly.
many thanks for the guidance everybody, it was a great head banging opportunity.