Deus Ex on Vista

Firstly, Are you running Duel Core? Most Vista computers do. If so, Start Task Manager (CTRL ALT DELETE), Right click on Deus Ex:

Then click on Affinity:

You can see your cores that you have, I have 4 so you can see them listed here, unselect all cores but one and press Ok.

This tells Deus Ex to only run on one core.

If you only have one core, ignore that and do the following:

Right click on your DeusEx.exe, and click on properties:

Click on Compatibility Tab, and click on "Run this program in compatibility for:"

Click on "Windows 98/Me" As seen here:

Click Ok.

If that doesn't work, try changing the graphics renderer, follow my Knowledge Base guide here:

If that doesn't work, try and attempt to run DX in 16bit colour, supposedly it helps some.

Those should solve any compatibility problems.