HI, try it in : SAFE MODE *https://support.mozilla.org/kb/Safe+Mode *https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes In Firefox Safe mode these changes are effective: *all extensions are disabled (about:addons) *default theme is used (no persona) *userChrome.css and userContent.css are ignored (chrome folder) *default toolbar layout is used (file: localstore-safe.rdf) *Javascript JIT compilers are disabled (prefs: javascript.options.*jit) *hardware acceleration is disabled (Options > Advanced > General) *plugins are not affected *preferences are not affected TEST'''''''''is issue still there ? If the issue is not there then it is 1 of your add-ons slowing things down. Update your Security Software. Can look through these to see if any help : *https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding *https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster *https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix *https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram *https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding Please let us know if this solved your issue or if need further assistance.