IE Authentication

Hi there,

I recently set up a network on 8 computers, which all have Internet access. There's an Internet Explorer icon on each of the desktop screens, which when clicked, takes you immediately to the default homepage. What I want to do here, is set up an authentication system, where you click on the IE icon, and you get a login box. If you don't enter correct details, you don't get access to the Internet.

Could someone please tell me how to go about doing this?

 

First of all, thanks for the prompt reply

Second, I tried that, and it works, but if you don't supply valid credentials it takes you to an error page, from which you can access the Internet from, so it's basically useless...

I think I have to set up a proxy server or something, don't i?