This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox will not start

  • 2 replies
  • 1 has this problem
  • 5 views
  • Last reply by sofi0518

more options

After my firefox updated from version 5 to version 6, it would not open. I did a restore to roll the version back and it still will not open. I tried to open the program in safemode and I got a message advising me that I was opening it in safemode but then it did not launch. If I start the PC in safemode, then it will open. I have completely uninstalled it, removed all registry entries and reinstalled it and I get the same result.

After my firefox updated from version 5 to version 6, it would not open. I did a restore to roll the version back and it still will not open. I tried to open the program in safemode and I got a message advising me that I was opening it in safemode but then it did not launch. If I start the PC in safemode, then it will open. I have completely uninstalled it, removed all registry entries and reinstalled it and I get the same result.

All Replies (2)

more options

A possible cause is security software (firewall) 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 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:

See also:

more options

Firefox was not listed in the firewall. I added it just to try it and it still doesn't come up. I am so frustrated. I hate IE...