Disabling Internet Explorer in W2k

In W2k I Removed the security settings for Internet Explorer (IEXPLORE.exe)and setup access thru use of an Internet Users group on the domain server. The problem is that whan a user tries to use the Internet Eplorer, they are denied access…..but when they go to the Windows Explorer, they can enter an Address into the bar and gain access to the Internet that way.

How can I disable this from happening.