When Firefox discovers a new extension on your system, for example, a toolbar from your security software, Firefox shows a page asking for your approval to install it in Firefox. Is that not working? If I misunderstood the kind of blocking you are experiencing, could you explain what is happening in more detail? You also can attach a screen shot to a reply, using the browse button below the text box. (This isn't possible with the original question.) This article has tips on creating a screen shot: [[How do I create a screenshot of my problem?]]