I spent the day making this work well on Windows 7 and now it has HD Textures, Widescreen capabilities, multi-core processor ready (Will just use one core instead of trying to use all cores and failing), and I re-binked the videos for widescreen as well.

I followed a tutorial on how to make it widescreen and did the bulk of the work for you and inclosed a hard to find texture pack.  I hope this helps people with the issues presented while running this game.  I credited the people who made the image, HD Texture pack, widescreen tutorial, Power ISO crack, and others, in a file called credits.txt.

Here's how to install it.

1.) Install PowerISO. (Included)
2.) Mount the Deus-Ex image to PowerISO and if it doesn't autorun, double click it in My Computer.
3.) Install the game and close out of everything.
4.) Install the HD Texture packs.  (Read "Making sure its enabled.txt" in the "HD Textures" directory to make sure it works.)
5.) Copy the DX2.exe file from the Crack directory over to the "C:Program Files (x86)Deus Ex - Invisible WarSystem" directory.  (Nix the (x86) on 32 bit systems.)  Be sure to backup the original.
6.) To use widescreen, follow the instuctions in the "Widescreen" directory.
7.) Enjoy!  =)

You don't need to have the disc stay mounted.

TROUBLESHOOTING:

Q.) Why is the text is missing from the game menu's, etc?
A.) For some reason the game isn't finding the required fonts.  You'll need to open the HD Textures Config tool and select "fonts" from the dropdown and click the red -.
    The tool is at: Start menu -> All programs -> Eidos -> Deus Ex - Invisible War -> Community Texturepack -> IBD Patcher