I'm on Windows 7. I would rather play Deus Ex in a window than in fullscreen. Unfortunately, when I try to play in windowed mode with either the normal executable or the kentie executable replacement, either the game crashes, becomes unresponsive, or my entire display's brightness settings get screwed up. What's going on here, and how do I fix it?

I attached an image of what was happening when I tried to run the game normally in windowed mode. (deusex.png)

I cleaned up the kentie files and got back to an error I was getting before when trying to run the game in windowed mode. (deusex-critical-error.png)

edit: I had some success using the software renderer instead of the D3D renderer, but the graphics were very glitchy in-game with lots of models clipping strangely and some not displaying at all. I tried switching to the OpenGL renderer and have been able to get it running in windowed without crashing or serious errors but I've got to go do something other than Deus Ex for now so I'll find out how well it works in-game later on.