When you install the game or demo dont install
DirectX uncheck this option.
After the install it will go through a first time setup
You will want to select "show all video options"
and select OpenGL software mode works as well!
If you want to play in a window you will have to go to
video settings and select the same x= y= settings
here as what you place in your config.
The demo can be found here:
http://www.3dgamers.com/games/deusex/downloads/
My settings
[AppDefaults\\deusex.exe\\x11drv]
; Deusex
"Desktop" = "800x600"
"Managed" = "N"
Tom