Good idea although I would have thought a video card that is capable of rendering the 3D graphics of the game without problems should be able to handle the FMV's. Maybe codec / driver issue? What spec is this older computer?
I'm a GeoForce 7300 GT 512 MB AGP on an AMD 2400+ Single Core.
The videos at default size will run through a player like VLC but in order for them to work in the game itself I had to resize them.