Sorry but it is always the other way. Norton needs to update their Firefox extension to work with the new major version Release so it can tie in with their antivirus client. The good news is that Norton as usual has a live-update patch for Firefox 33.0 which was available on October 13, the day be fore Firefox 33.0 was Released. *http://community.norton.com/forums/firefox-33-support-norton-toolbar-0 *https://community.norton.com/blogs/product-update-announcements/firefox-33-und-norton-toolbar As for the black screen it may be due to old graphic drivers https://support.mozilla.org/en-US/forums/contributors/710777?last=62406#post-62379 start Firefox into safemode '''by pressing the shift key while the application is launching''' & disable Hardware Acceleration in the Firefox ''menu ≡ > Options > Advanced > General'' (You will need to restart Firefox to take effect).