You may want to update your Video Card Drivers 8-4-2015 was last time. https://www.intel.com/content/www/us/en/support/products/80939/graphics-drivers.html Old drivers cause issues. Which I noticed a couple. Note below is to check, there could be other issues involved here. Check to : See if Multi-Processor Support is turned on. Multi-processor support feature may be disabled depending on your setup (it was for me) - you can check this by launching Firefox, then enter in "about:support" in the address bar; near the bottom, you should see a heading that says: "Multiprocess Windows", then look at the value next to it. If it says "0/1", then that means it's disabled. 0/2 and higher = on unless says it is off. Then check the Task Manager and see how many instances of Firefox is running and what the memory numbers are like. If need to can turn off multiprocessor : You can try to modify multi-process settings to see if this has effect. You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue. set dom.ipc.processCount to 1 if it is currently set to a higher value (4) disable multi-process windows in Firefox You can disable multi-process windows in Firefox by setting these prefs to false on the about:config page. browser.tabs.remote.autostart = false browser.tabs.remote.autostart.2 = false http://kb.mozillazine.org/about:config Also can reverse everything this tells you to enable it. http://www.ghacks.net/2016/07/22/multi-process-firefox/ Please let us know if this solved your issue or if need further assistance.