http://kb.mozillazine.org/Firefox_crashes

I know this page. It doesn't solve my problem. In the past I'v used Firefox on this computer now it is not working anymore.

Have you tried uninstalling Firefox (but not the profile), removing the program directory, then reinstalling it?

http://kb.mozillazine.org/Standard_diagnostic_%28Firefox%29

Any chance you have the Speedbit Video Accelerator installed in Windows?

As far as having no plugins installed, did you look at the Plugins list in the Add-on Manager tab? I find it very strange that Firefox couldn't find even one plugin that it would use - unless that is a fresh installation of Win XP.

Any chance you have the Speedbit Video Accelerator installed in Windows? I don't think so, really I don't know. How can I see if the accelerator is installed?

As far as having no plugins installed, did you look at the Plugins list in the Add-on Manager tab? I find it very strange that Firefox couldn't find even one plugin that it would use - unless that is a fresh installation of Win XP. Firefox crashes at startup, so I cannot check/see anything in Firefox. With no plugins installed I mean no extra add-ons/plugins installed.

The crash reports a problem with the advapi32.dll file that is part of Do a malware check with some malware scanning programs on the Windows computer.
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.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/security/scanner/en-us/default.aspx - Microsoft Safety Scanner
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Thanks for your reply. I have scanned my computer with Anti-Malware, SuperAntiSpyware, Microsoft Safety Scanner, Search & Destroy and TDSSKiller. It does find a lot of cookies, etc. but nothing which harms my computer. After repair I have still the same problem, e.g. a crash of Firefox at startup. The crash window is the first window shown. Do you have another suggestion what might be wrong?

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

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

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

You can also try a clean reinstall and delete the Firefox program folder (C:\Program Files\Mozilla Firefox\) before reinstalling a fresh copy of Firefox.

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

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, to cleanup the Windows registry and settings in security software.

• 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.

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

Creating a new profile doesn't solve the problem. Starting Firefox with the parameter -p the profile manager is shown and it crashes again without the possiblity to modify anything.

Uninstalling Firefox, removing the program files folder and reinstalling the English version of Firefox 14.0.1 also doesn't solve the problem.

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.

In safe mode Firefox starts and shows the home page!

I cannot find which program/process/service conflicts with Firefox. It costs me too much time. I have installed a clean OS and now everything is ok! Anyway thanks for your help.