Display Properties Windows2000.

We have a problem with employees changing the display properties on thier displays. Many of these changes consist of fluorescent color combinations that make it all, but impossible to work with those stations. this is a mill setting. the problem hasbecome large enough that it takes up a lot of our time changing these screens back to thier original settings. we have already had to take away the games. there must also be a way to take away a users ability to access the display properties unless they have admins rights. any suggestions?