installing QuickTime on the PC won't help. PowerPoint for Windows as a general rule *will not* play QuickTime clips. Period. End of story. Okay, there is a way if you use an ancient codec that mplay.exe can handle, but those codecs are few and far between. You cannot play a QuickTime clip embedded in a PowerPoint slide on Windows. In that way, PowerPoint is far from cross-platform.
What you CAN do with Windows PowerPoint is to place a link on the slide which will fire off QuickTime Player, from which you CAN play QuickTime movies. If you set the movie (using QuickTime Player) to "Play Full Screen", "Play On Open" and "Close When Finished" you can set it up so that when you trigger the link on the PowerPoint slide, the movie will play full-screen, then close by itself so that you can return to PowerPoint. Perhaps not the best workaround, but it does work.
Why PowerPoint can't just use the QuickTime ActiveX Control the same way that Internet Explorer does is beyond me.......
--Dave Althoff, Jr.