I have single laptop at home. Yesterday for first time, couldn't get into Firefox as it said "The Proxy Server is refusing connections". Obviously I don't use a proxy server. Went into Internet connections and the proxy server box was ticked, so I unticked it and all is fine. But how could that have got ticked? Doesn't seem possible that a couple of accidental keystrokes could have done this? Only my wife and I use the lapotop so no one else could have played about with settings.