When trying to go tools -> options my FF crashes, same happens when I try to download anything. Same happens when I run FF in safe mode, creating new profile, deleting any files in profile folder, uninstalling and installing FF = doesn't change anything. This happens with newest Firefox 17 and with Firefox 3.6 but DOES NOT happen in Firefox 2.0 (however I can not use that old browser because for some reason I can't import bookmarks from .json file). I searched whole web looking for solution, many people had the same problem and removing some program called Tortoise helped them, but I have never used that. I'm desparate cause I think after wasting so much time most people would just switch to other browser but I can't do that cause no other browser can recover my bookmarks from .json file.