error message "Unable to create Direct3D9 device"

 From:  Michael Gibson
2124.2 In reply to 2124.1 
Hi Jotell, have you turned off hardware acceleration in XP for some kind of compatibility with another program? I've heard from a few people who turned it off for some reason (like to use a certain kind of screen recorder, etc...) and then forgot to re-enable it, which is one thing that will result in that error message. The other thing that can cause it is if you have a very old video card that does not support the base 3D features that MoI needs to run, but I don't think that is the case for your situation if you can run fine with the same machine under Vista.

One thing you can try is go to Start / Run and type in dxdiag.exe

That will run the "DirectX Diagnostic Tool". Go to the Display tab and there is a button there labeled "Test Direct3D" which you can use to run some basic tests to see if the Direct3D system is working or not. There is also a button there for enabling Direct3D Acceleration if it has been disabled for some reason. If it is something that was disabled in the driver settings you may need to go back to the driver settings to enable it again though.

Hopefully that may help,

- Michael