please : go to the Firefox 3 Bar Menu --> Options --> Privacy & Security panel and under Permissions check (put a tick in the box) the setting to Prevent Accessibility Services from accessing your browser. Monitor in Task Manager. Should stay below 2 gigs. If excessive then do below and monitor and change if need to...Test and go up again , go back down, it will eventually get a zone you and it can live with. Go to the 3 Bar Menu then Options --> General --> Performance and untick everything. change the recommended size lower then see how it runs. Note: 1 = No Multiprocessor = slow again. Try 2 Restart Firefox after making these changes please. ____________________________________________________________ Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox. A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there? *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.