You should search for the following files, if they are on the main disk , most likely you do support shadow copies of the file: C:\Users\${USERNAME}\AppData\Roaming\Mozilla\Firefox\Profiles\${PROFILENAME}\sessionstore.[js,*]
To turn on Direct2D: Go in to about:config and set mozilla.widget.render-mode to 6, and gfx.font_rendering.directwrite.enabled to true. To turn off Direct2D, once it is on by default, set mozilla.widget.render-mode to 0. To check whether you are running with Direct2D,…
about:config layout.spellcheckDefault value to “2″ restart firefox
Clear Firefox Data Ctrl+Shift+Del
C:\Program Files\Mozilla Firefox\plugins , копираш NPSWF32.dll(x64) или WPSWF32.dll (x32)