The toolbar works perfectly on my Vista 32 bit laptop. However, problems persist on my Win 8.1 64 bit PC on Chrome but not on IE or Firefox. I don't know whether it is a Chrome or Norton problem. When the toolbar repeatedly went missing on boot-up, Support staff kindly remotely reinstalled the toolbar three times but removed the other two extensions which I want to use (an ad blocker and "Tabs to the front"). An updated toolbar was installed in the latest remote session.
I have re-installed the other two extensions but the toolbar now only appears after PC boot-up using an irritating procedure found by trial and error. Run Live update until "Not required" appears - Restart - open IE and sign in to Vault, open Firefox as well with Vault open - open Chrome too. The toolbar then remains except, as another commenter said on the forum, the top of some webpages is covered by the toolbar - sometimes covering link buttons. After exiting IE and Firefox, the toolbar now remains in Chrome after Sleep mode but not after Restart or Shutdown.
I was thankful to be notified by Norton that updates will be made available for Windows 10.