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Mozilla Firefox Won't Start

Treadstone21 asked
I installed Mozilla Firefox and it won't even start up.
I removed it and re-installed it and it won't even start up. When you ever you double click the Icon (execute it) it does'nt work.
I currently use IE7 with all the updates.

What do you suggest. This is important to me so I'll put 375 points.

Many Thanks
Watch Question

Top Expert 2008

Hello Treadstone21,

1. An addon may be interfering with IE. Disable Addons.  Start IE in No Add-ons mode, either by right-clicking the Desktop icon, or clicking START | RUN and typing: iexplore.exe -extoff

If Firefox can open, go to Tools > Add-on Manager, and uncheck the addons.  Then put back one at a time to see which addon is the culprit.

2. Reset IE settings.  Go to Tools > Internet Options > Advanced.  Click on "Reset" button. Click OK. Close all browsers. Reboot the computer.

3. Check if a program running in the background is interfering with Internet Explorer. Temporarily disable antivirus, firewall, antispyware, ad-blocker, popup blocker, and all Norton programs.

4. Uninstall and reinstall IE7. Make that antivirus and other security programs are turned off in the background.

Make sure you have the latest updates.

Hope this helps!


A little more information might help us pinpoint your issue, also.

What Operating System are you running?  
What Security programs dod you have installed on this machine?
Have you EVER had Firefox running successfully on this machine?
When you installed Firefox, did you Import settings from IE?  I would not.

When you installed Firefox, were you running as an Admin? And did you then Run it at least once, as an Admin of the computer?

Most importantly, is this YOUR machine or a Work Computer?  Some companies have tried to prevent Firefox from being installed on theri machines.

Are you having issues accessing the net on IE at all?
Have you checked this machine for virus/malware?

See http://kb.mozillazine.org/Standard_diagnostic_-_Firefox until we get back to you.


I tried what war1 suggestion and it did'nt work, unfortunately.

I am running Windows XP Home service pack 2.
I have AVG spyware and ativirus (free editions). I had spybot and avast running at one time.I also have cc cleaner runnig, it runs at sart-up.

Yes a had Firefox running successfully on this machine at one time. I a imported IE setting. Funny thing is it did ask to import any settings recently.

Yes I was an admin at the time and successfully used the webrowser.
This is my personal machine and I ran spybot, avg (both) avast and cc cleaner.

I hope this helps
Top Expert 2008

I gave you th directions for IE7, not Firefox.  Try these suggestions.  You may have to perform steps 4 or 5 to fix the problem. Try the other steps first.

1. Check if an addon is interfering.  Go to Tools > Addons and disable the addons. Click OK.

2. Check if a program running in the background is interfering. Disable firewall, antivirus, antispyware, spam blocker, and desktop programs.

3. Clear your cookies and cache files. Go to Tools > Options > Privacy tab. Under Private Data, click "Clear Now" button.  Click OK.

4. If no joy, your profile is corrupt. Create a new Firefox profile

Then migrate your settings to new profile

5. If no joy, back up your bookmarks.  Uninstall Firefox and delete your Firefox profile files.  Then do a clean install of Firefox.


War1 is most likely correct.  A new Profile is in order.  Uninstalling and reinstalling Firefox does not effect your Profile, which is why it did not ask you to import from IE.  If an install of Firefox finds an existing Profile, then it uses it, without creating a new one. But if you have a corrupt Profile, Firefox does not know that and tries to use it, which would explain why removing Firefox and reinstalling it had no effect on the browser.  Basically when Firefox is installed, the program is installed to "Program Folders", but the preferences of the user are set to the "Profile Folder" typically located in the Documents and Settings directory.
See for more info regarding it. http://kb.mozillazine.org/Profile_Folder

Although the Standard Diagnostic I pointed you to should have had you create that New Profile.

Let us know if you have any more questions or problems.


OKk, I'll try that and let you know.


war1 - you are a Bad Boy!
I could'nt even get to create a new profile. Nothing for Mozilla would start.
So I uninstalled it and deleted everything for firefox (expect other programe's extentions) and re-intalled it and that did the trick.
Thanks man!
Top Expert 2008

Treadstone21, glad the problem is fixed.