Sounds to me like its a group policy or domain controlled issue...in which case, your options are limited...
Try going to Microsoft Management Console (MMC),
then open Local Computer Policy, User Configuration, Administrative Templates, Control Panel, and Display.
Chances are you won't have the rights to do this, but if your I.T. administrator missed something, it's possible that you will be able to do it.
Other than this option, I think you are out of luck, unless you contact your I.T. administrators and ask them about it.
Hope this helps!
Also if this is not on a domain, you can go into control panel and right click display and click run as admin. If you know the admin password that is. That might help as well.