Create a new profile as a test to check if your current profile is causing the problems. See Basic Troubleshooting: Make a new profile There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" If that new profile works then you can transfer some files from the old profile to that new profile (be careful not to copy corrupted files) See http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox See also http://kb.mozillazine.org/Firefox_crashes