When I started your demo and the profile selection screen popped up, the window size was extremely small, so I pressed F5 multiple times and F11 once to check the resolution (in fullscreen). When I got my desired resolution, I hit F11 again and the game started to glitch. Then my computer froze for some seconds, made some beep noises and shut down while giving some error messages (explorer.exe stopped working and the like, I don't know how much that was related to your game, maybe not at all?).
I'm using Windows XP, SP3.