2KTS backgroud blue

Hi, Does anyone know how to change the backgroud of the login screen to black? I did a right click on the desktop and went down to properties and changed my desktop to black but the login screen still comes up blue. How can I change that screen.
P.S. I believe it has something to do with Active Destop but I am unable to find a way to shut it off.

Comments or suggestions would be appreciated.

Thanks

Jody