when i try to open firefox the message "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window" appears and then i press on close window button again a popout appears saying "Your Firefox profile cannot be loaded. It may be missing or inaccessible" I tried uninstalling and installing firefox a lot of times and I deleted firefox folder in Appdata folder to remove parent lock and rest of stored data I tried Normal startup option in MSConfigure and then firefox opened first time and second time it again shows same popout. But if I set firefox not to store any kind of history the firefox working even though it sometimes shows the pop-up "Firefox is already running, but is not responding. The old Firefox process must be closed to open a new window".