The tutorial movies require the EnSharpen codec, which you can download here.

Part 3A Data Sources & Import	QuickTime Movie 3:39	HTML Tutorial	.
Part 3B Tiling & Layers	QuickTime Movie 10:42	HTML Tutorial	Project at the beginning of this section: VNS 3 DVD: WCS\WCSProjects\Tutorials\YNP\YNP3B.proj
Part 3C Downsampling Terrain	QuickTime Movie 3:33	HTML Tutorial	Projects at the beginning of this section: VNS 3 DVD: WCS\WCSProjects\Tutorials\YNP\YNP3C.proj
Part 3D Generating Terrain	QuickTime Movie 3:46	HTML Tutorial	.
Part 3E DEM Painter	QuickTime Movie 4:49	HTML Tutorial	Project at the beginning of this section: VNS 3 DVD: WCS\WCSProjects\Tutorials\TG\TG3E.proj
Part 3F Fractal Depth	QuickTime Movie 5:32	HTML Tutorial	Project at the beginning of this section: VNS 3 DVD: WCS\WCSProjects\Tutorials\TG\TG3F.proj