I think I can answer where it came from since I'm the guy who uploaded it to Google video...
Back in the late 80s I was fresh out of High School and working for Software Etc. when Microsoft sent that tape out. A buddy of mine kept it all these years and recorded it (to his Mac!) and asked me if I wanted a copy of it.
"A copy of it!?! We have to put it on the Internet!"
So he sent me the 100+MB file which was too big, I cut it down to size using a video editor for the PSP. Even then it was still too long for YouTube (10 minute max) so I put it on Google instead.
I'd say I still have the better quality version if anyone wants it... but better quality is very much a relative term. :^)
Glad to see it's bouncing around and causing mirth.