I am very comfortable with my Firefox 25 version and see no need to upgrade it. Every time that I have done so previously has caused me unendable problems in that all my favourite sites are no longer accessible and my familiarity with the site I know has disappeared. I am fed up with being hectored to upgrade every time that I switch on my PC to upgrade to some new version. I have very efficient virus protection and do not need any further protection (indeed it has previously been in conflict with my installed system. So why do I need to update and how do I ensure that I am no longer pestered to update my system. Surely I can set my PC up so that I do not get "update requests" every time I go onto the internet.