At work we run two web browsers namely IE and Firefox.  IE usage is on the decline as everyone is working out that IE is crap for AJAX interfaces which is what our webmail system uses.  So most people are using Firefox as it is so much faster this posed a little problem.  With Active Directory you can easily push out and lock Proxy settings for IE. 

To do with Firefox some file changes on the application itself must be set, so on our terminal servers we’ve done the following;

1. Open a Text Editior and create a file called mozilla.txt in it add the following lines.
   •  lockPref(“network.proxy.http”,”mypoxyserver”);
   • lockPref(“network.proxy.http_port”,3128);
   • lockPref(“network.proxy.type”,1);
   • lockPref(“browser.startup.homepage”, “myhomepage”);
2. Then byte shift the file with an offset of 13, you can use this service to do it for you.
3. Copy the new file without editting it again, to the Firefox.exe directory as mozilla.cfg
4. Navigate to C:\Program Files\Mozilla Firefox\greprefs and open the file all.js in a text editor
5. Add the line pref(“general.config.filename”, “mozilla.cfg”); to the start of the file and save.

Now when any user starts the application the homepage and proxy settings will be locked.