There could be more than one reason for such messages. There is a problem sometimes with the database file used for history and bookmarks see * http://blog.bonardo.net/2011/09/30/is-your-firefor-freezing-at-regular-intervals There was a change made which seems to affect some Windows users, and has a workaround, but tends to result in images etc not loading rather than a not responding message see * [[firefox never finishes loading certain websites#w_lower-the-max-number-of-http-connections]]_lower-the-max-number-of-http-connections Are you getting any other error messages, or indications of problems ? * not directly related to an update but also see [[firefox hangs]] * and [[Firefox is already running but is not responding]] ------- P.S. <br/> I note you have BrowserPlus, that has sometimes, recently, been associated with firefox problems, it would certainly be worth trying temporarily disabling that.