Win2003 Group Policy Manager

Hi,

I am very new to Group Policy Management. I have done the following. Used gpedit.msc to edit the pop-up allow list settings for Admin Templates/Windows Components/Internet Explorer.
I set this for Computer and User configuration.
The problem is that it does not seem to be pushing the policy to any machines. How can I force this and other policies to go into effect?

P.S. I just chose this specific policy to try to get an understanding of the GPO.

Thanks,

Kevin