Block IE From Accessing Internet

1. Modify Internet Explorer To Use A Proxy Server 
 
The first step in this two step process is to trick Internet Explorer into accessing the Internet using a dummy proxy server. By default your LAN settings in IE are usually set up to automatically detect your Internet connection settings. We’re going to change that.
First, go to Tools -> Internet Options -> Connections -> LAN Settings.

First, uncheck “Automatically detect settings” and select the option to use a proxy server.  Set the address to some dummy IP followed by port 80. It doesn’t matter what you use, just make sure it isn’t a real server.
Nice! Mission accomplished right? Wrong! All one has to do is open up the Internet Options, click on “Automatically detect settings” and he/she’s back in business. So the next step is to disable every user’s ability to tweak the IE Internet options settings.

2. Disable Internet Options In The Control Panel

To do this, click Start -> Run and type “Regedit.exe“.

Go to My Computer/HKEY_CURRENT_USER/Software/Policies/Microsoft/Internet Explorer/Restrictions. You may have to create the Internet Explorer and Restrictions keys if they aren’t already there. Then, create a new DWORD called “NoBrowserOptions” and set it equal to 1. Now, restart Internet Explorer.
You still won’t be able to browse anywhere, because it’s defaulting to the proxy server. So, go ahead and try to access Tools -> Internet Options. Your little ones will be faced with the following warning.

This effectively blocks most normal users from accessing the Internet through IE. An especially clever user will just go to the Control Panel and enable the Internet Options that way, so you’ll also need to disable those control panel settings in the registry as well.

 Go to My Computer/HKEY_CURRENT_USER/Software/Policies/Microsoft/Internet Explorer/Control Panel (or create the key if you have to). I’ve added several policy restrictions to the control panel, but the important one here is the DWORD ConnectionsTab. Setting this to 1 will disable the Connections tab in the control panel, so the user can’t change the Internet settings from the proxy you set up.

You’ve completely blocked IE from accessing the Internet, and the only thing that a clever user could do to fix it is to find the right registry keys and fix them. So, this won’t block a seasoned geek, but it’ll at least keep people from opening up the wrong browser! Be warned that there are some Internet applications that make use of the connection settings in your Internet Options. Most applications allow you to configure proxy settings from within the app itself, but not all – so if any of your Internet apps don’t work after you lock down IE, this is probably why.

Have you ever had the need to block IE from accessing the Internet? Does this technique work for your application? Share your own experiences and how you have blocked your own Windows Internet Explorer access to the Internet.