See firefox crashes it will probably help if you are able to obtain a crash signature.

It is also worth noting that there is certain malware about that may cause Firefox 6 specifically, to crash. If possible it would be a good idea to rule this out as a possible cause of crashes by doing a full system security scan with up-to-date security software. I think I am correct in saying Microsoft provides security software free of charge to registered customers.

(If it is a malware problem upgrading to Firefox 7 may solve the crash problem BUT it will not solve the malware problem)

Post back with how you get on.

Of course I checked firefox crashes. I searched and haven't found my problem. I used Firefox 5 when it happened, then, seeing it doesn't work no matter what I do, I upgraded to 6. The same problem. So it's not 5 or 6 related. Computer probably wrote something to hard disk when it crashed and now the file is corrupted and prevents Firefox from starting. I don't know what file (or part of the registry) is. I could erase everything, but that would mean I will lose every Firefox settings and I don't want that. Now I am using Google Chrome to write this. I miss my Firefox. :( What else can I do ?

This is the error I get when I try to start Firefox:

Have you tried starting Firefox in safe mode either by using a run command line or by holding the shift key (Option Key on a Mac) when starting ?

If you are careful it is possible to uninstall Firefox and reinstall it without loosing personal information. To do that you must take care NOT to take the option to delete settings (however it is worded). It is possible to delete the Windows Program files folder without loosing personal info because that info is stored in a separate location the profile.

Whether re-installing will help depends partly an what causes the problem at present. If you read Firefox Crashes you may also notice the link:

• https://support.mozilla.com/en-US/kb/Firefox%20crashes%20when%20you%20open%20it#Getting_your_crash_report

Have you tried to discover crash IDs and Crash signatures yet? As explained in the above article this procedure may be completed with another browser if Firefox is not useable.

Have you done a full system scan for Malware?

• if so when, and what did you use ?

The next step may be to do a clean install or create a new profile, but at least try the malware scan and safe mode first.

Nothing happened, thanks John for the effort, but I got it on my own. The problem is Firefox 6.0. It doesn't work for me. It won't start no matter what and all I got is the error mentioned above. I scanned everything, registry, Windows, everything. Nothing. I uninstalled Firefox (I kept the profile in a different location on my hard disk) completely and re-installed Firefox 5.0 and applied the profile. Everything is working fine. Somehow Firefox downloaded version 6.0 on it's own, installed it and it couldn't run. That was it. Now is the problem for Mozilla why Firefox 6.0 isn't working for me. I'm sure there are others like me with the same problem. Again, thanks.

Thanks for posting back with an update.

Firefox 6 works fine for me, and has done for a while ( It was released on the Nightly, Aurora, and the Beta Channels prior to the Release to general users).

I imagine many millions are using Firefox 6 without problems. Downgrading to Firefox 5 may only be a temporary solution.
Whilst I am glad Firefox is again working for you this may not be the end of your problems.

Downgrading to a previous version is not a solution. When you decide to Upgrade back to Firefox 6.0 and see the problem again, we'll help you resolve it.

Well, you can help me now. But what can I do ? It won't start.

Troubleshooting extensions and themes

• https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes

Clear Cookies & Cache

• https://support.mozilla.com/en-US/kb/Template:clearCookiesCache

Clear the Network Cache

• https://support.mozilla.com/en-US/kb/How%20to%20clear%20the%20cache#w_clear-the-cache

Troubleshooting plugins

• https://support.mozilla.com/en-US/kb/Troubleshooting%20plugins

Check and tell if its working.

First link: I can't start Firefox in safe mode. I tried it before. It just won't start at all, safe mode or normal mode.

Second link: To clear cookies and cache, you have to start Firefox. It won't start.

Third link: Same as second. Firefox won't start.

Fourth link: Plugins are working fine with Firefox 5. While this may be the problem, I can't do nothing about it. I need those plugins. Those are standard plugins anyway, nothing fancy. You know, shockwave, etc. Anyway, tampering with plugins looks complicated.

-> Create a New Profile as a test to check if your current profile is causing the problems.

-> Basic Troubleshooting: Make a New Profile

• https://support.mozilla.com/en-US/kb/Basic%20Troubleshooting#w_8-make-a-new-profile

-> If that New Profile works then you can recover your Bookmarks and Passwords from the Old Profile.

-> Recovering important data from an old profile

• https://support.mozilla.com/en-US/kb/Recovering%20important%20data%20from%20an%20old%20profile

Check and tell if its working.

I did a new profile. Same error message I posted before. Please check the picture I attached previously.

Other solutions

• https://support.mozilla.com/en-US/kb/Basic%20Troubleshooting#w_other-solutions

Do a MALWARE check with these Malware Scanning programs. You need to scan with all programs because each program detects different malware. Make sure that you UPDATE each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware - http://www.malwarebytes.org/mbam.php
• SuperAntispyware - http://www.superantispyware.com/
• Windows Defender Home Page -

http://www.microsoft.com/windows/products/winfamily/defender/default.mspx

• Spybot Search & Destroy - http://www.safer-networking.org/en/index.html
• Ad-Aware Free - http://www.lavasoft.com/products/ad_aware_free.php

There are also specialized forums for Malware Removal such as those listed below, where you might be able to get more help:

• Bleeping Computer Forums - http://www.bleepingcomputer.com/forums/
• Spyware Warrior Forums - http://www.spywarewarrior.com/index.php
• SWI Forums - http://www.spywareinfoforum.com/

Check and tell if its working.

mha, why ferociously trying to avoid the most obvious and try too look in every other place then the Firefox itself ? That version simply won't work on my computer and current configuration as it is. And I'm sorry, but I won't mess my computer installing and running all sort of programs just for the sake of one version of Firefox which clearly has some issues. As a curiosity, IE8 isn't working on my computer as well. I don't know why. Maybe the new versions of programs are so complex, it's quite hard to make them work along will all other programs and with such a diversity of hardware available today. As situation is, I did ran malware and spyware programs. You know how those are. They always found something bad, just to justify their existence, but most of them are just rubbish. I did however repaired the "bad" entries in registry, no viruses, no spyware, malware, etc. Simply, Firefox 6.0 won't run, because something is preventing it to run. I just don't know what. Maybe incomplete programming inside Firefox 6.0, maybe a contradiction of other software on my computer, maybe hardware (although I doubt it), I don't know. And yes, I noticed the crash report and I sent it to Mozilla.

OK, I must edit this post. I will leave everything as it was, since I don't want to be accused of deleting previously posted information.

The weirdest thing. And with this, everything is in complete darkness. I installed Firefox 5.0, and after I worked with it for a while, I checked the version and it says 5.0. Immediately it started to download the latest version from the "about Firefox" window and, although I told it to not install it, on the next run, it upgraded itself. To my surprise it says Firefox 6.0 now and it's working. :O

I have no idea why. Why it didn't worked before, why it stopped working and all attempts to install 6.0 directly failed and installing 5.0 and then upgrading it from inside it, made that work ?!?

I am not inventing things, I am not abusing others and my time, but that was what happened. On one hand I am happy I solved the problem, but since I don't know how it got itself repaired, the issue may reappear.

And... I spoke too soon. :( The same error. And again, Firefox won't start. Is there a way I can disable Firefox in updating itself ? I really could use some help, this is very annoying and I really don't want to leave Firefox and migrate to other browsers.

-> Download Firefox (version of your choice)

• http://releases.mozilla.org/pub/mozilla.org/firefox/releases/

-> Start your WINDOWS in Safe Mode -> Completely Uninstall Firefox

• https://support.mozilla.com/en-US/kb/Uninstalling%20Firefox
• http://kb.mozillazine.org/Uninstalling_Firefox#On_Windows
• You can use some third-party Uninstaller Software (like Revo Uninstaller, etc.) for your satisfaction

-> Installing Firefox on Windows (use the downloaded Firefox installer file)

• https://support.mozilla.com/en-US/kb/Installing%20Firefox%20on%20Windows
• http://kb.mozillazine.org/Installing_Firefox

When Firefox is installed, see this - How do I Configure Update options?

• https://support.mozilla.com/en-US/kb/Updating%20Firefox#w_how-do-i-configure-update-options

Check and tell if its working.

You said before, I can't start Firefox in safe mode. I tried it before. It just won't start at all, safe mode or normal mode.

If Firefox 6 also crashes when you try to start up in Firefox Diagnose Firefox issues using Troubleshoot Mode then see Firefox crashes when you open it for possible causes.

See also http://kb.mozillazine.org/Firefox_crashes#Crash_when_starting_Firefox

If you are able to start Firefox when you reboot in Windows Safe Mode then that would point to malware that is active on your system in normal mode.

Also, try to get a crash report the next time you are able to start Firefox and post a link here.

I do have a crash report, but cannot interpret it. I sent it to Mozilla.

You need to post a link to the most recent report on the "Submitted Crash Reports" page you get when you enter about:crashes in the Firefox address bar.