Hello again!
Is there a way to prevent users from switching away from the full screen application? Also, if it does switch away, when I put it back on fullscreen, I get an empty frame.

The purpose of the application is to prevent users from using my laptop. I display an image, and as soon as the user plugs in their USB drive, the program closes.

Thanks!

http://www.allegro.cc/manual/api/graphics-modes/set_display_switch_mode

Though you also want to look up how to disable the CTRL+ALT+END combination Allegro has built-in and you'll also want to find out how to disable the CTRL+ALT+DEL combination built into Windows, because that combination will still work even if you disable Allegro's CTRL+ALT+END and there's nothing Allegro can do to stop it.

--- Kris Asick (Gemini)
--- http://www.pixelships.com

You can't stop ctrl+alt+delete.

Why do you need to use an Allegro program to do this though? What's wrong with Windows built in locking? Win key + L or ctrl+alt+delete->lock computer (if you have the pretty login screen on XP disabled) will be way more secure.