Well, Just a warning b4 running the proof of concept... Make sure to close and save useful stuff. It indeed works on xp sp2 and it will reboot your machiene. I have to say, This would be trick to exploit another programs messagebox, and wha joy could you possibly get out of restarting someone computer. I dont think there is possiblility for any code execution, as far as I seen. Would be a nice S-Kiddy toy if you could do it remotely, but would also piss off alot of people.