I happen to have the entire Back to the Future The Game episodes so I decided to install them all on my new computer.
However, after having done that, I noticed there were only 4 games appearing on my Start menu. I checked my Program Files to make sure they were in there, but then I noticed that only 4 out of the 5 episodes appeared on my Games Explorer folder.
Right now I'm actually trying to edit the registry so that I can add an Episode 4 icon seeminglessly into the list (by exporting, editing, and reimporting the reg keys on the GameUX entry). I think I've been pretty successful so far, except I can't seem to find the actual Game Description text for this Episode anywhere (thats the description popup that displays when you hover over the icon). It's the part that goes "In this episode,...".
I have Windows 8.1 btw.