Unfortunately, MediaLab has about zero capability to affect a PowerPoint show once it's running. Consequently, you would need to find this solution through people who know PowerPoint better than I. If the option doesn't exist within the PowerPoint Preferences, you might look online for PP macros to intercept the key presses and nullify them. I'm surprised there is no way out of Kiosk mode. Just did an internet search and turned up that you can exit Kiosk mode by pressing Escape. Have you tried that? If so, maybe you could create a final screen that says "Press Escape to Continue"?