After I launch an initial website and go on to other related sites, multiple locations appear on the task bar. When I complete my web visits and click out of all the sites and close out of Firefox I assume that the browser is no longer active. When I attempt to restart the browser, it will not launch. When I close down my laptop, a message appears telling me that Firefox has to shut down. To me this indicates that Firefox has been running in the background when I have shut it down. The only way I can get Firefox to relaunch is to shut the computer completely down.