Can you open Firefox? ---- Create a new profile as a test to check if your current profile is causing the problems. See "Basic Troubleshooting: Make a new profile": *https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile If the new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files. See: *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox ---- Also check for problems with your security software (firewall). See: *https://support.mozilla.org/kb/Server+not+found *https://support.mozilla.org/kb/Firewalls

Thanks for your help; however, unfortunately creating a new profile didn't work. Further, I cannot even access the Firefox website, just the about: pages.