See:

• http://kb.mozillazine.org/Browser_will_not_start_up

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

You can try to boot the computer in Windows Safe mode with network support (press F8 on the boot screen) as a test to see if that works.

I thought i explained i did that. Will do one more time, but other than that guess FF will no longer be a part of my life on my only computer/laptop. Too frustrated! Havent tried Safe mode, but whats that gonna tell me? Its not gonna fix my problem I tried different configerations seems if I choose Win 95 or Win 98 it will work for a bit, when shut down computer wont work at all again then have to troubleshoot and and put in Win 95 or 98 again.... so someways it can work, but not continuously without problems. Maybe that will help you, explain to me more detailed how to run FF now, rather fix it permanently as it is possible. and if you show me that stupid extension page, Im just gonna give up completely cause thats just ridiculous...perhaps you can do it for me. I dont understand at all, how come Chrome hasnt had any problems?

Do a clean (re)install and delete the Firefox program folder (C:\Program Files\Mozilla Firefox\).

Download a fresh Firefox copy and save the file to the desktop.

• Firefox 14.0.x: http://www.mozilla.org/en-US/firefox/all.html

Uninstall your current Firefox version, if possible.

• Do NOT remove personal data when you uninstall your current Firefox version, because all profile folders will be removed and you will also lose your personal data like bookmarks and passwords from profiles of other Firefox versions.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

• It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
• http://kb.mozillazine.org/Uninstalling_Firefox

Your bookmarks and other profile data are stored in the Firefox Profile Folder and won't be affected by an uninstall and (re)install, but make sure that "remove personal data" is NOT selected when you uninstall Firefox.

• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Profile_backup

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall