When you shut down Firefox use '''File > Exit''' or '''Firefox-button > Exit''', closing by the Close button in the upper right-hand corner closes the Window but that does not mean that it will also close Firefox. To make sure Firefox is down and when you get the message Firefox is still running you will have to close it through the Windows Task Manager "Ctrl+Alt+D" > "Start Task Manager" > "Processes" tab > right-click on "firefox.exe" and choose "Close tree" This has always been true of using Firefox on Windows systems.