[https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Start Firefox in Safe Mode] {web link} A small dialog should appear. Click '''Start In Safe Mode''' (not Refresh). Is the problem still there? 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 https://support.mozilla.org/en-US/kb/firefox-takes-long-time-start-up https://support.mozilla.org/en-US/kb/quick-fixes-if-your-firefox-slows-down MemTest LAST UPDATED : 12/04/2020 Could you please run a tool from http://memtest.org/ in order to check the integrity of your RAM? You will need a thumb or disk drive to install it on. Do you let Windows handle the page file or did you set a fixed size ? If you use a fixed size for the page file then try the former and let Windows handle the page file.