changing settings behind the firewall

I'm behind the firewall. I want to change my desktop settings like changing the color. I'm bored with the preset colored gray desktop and i want to change it. It doesnt allow me to do that. I'm getting The operation has been cancelled due to restriction of this computer msg. Is it possible to to disable that? how?

By the way, I'm using win 2000
File system: NTFS

Your problem isn't the firewall, it's the policies enforced on your computer. . .someone doesn't want you to be able to change these things. . .best way to get to be able to mess w/ the settings is to ask the admin/owner of the computer.