Do a clean (re)install:

• Download a fresh Firefox copy and save the file to the desktop.
• http://www.mozilla.com/firefox/all.html
• Uninstall your current Firefox version and remove the Firefox program folder before installing that copy of the Firefox installer.
• Don't remove personal data if you uninstall the current version.
• 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.

Your bookmarks and other profile data are stored elsewhere (not in the Firefox program folder) and won't be affected by a reinstall, but make sure that you do not select to remove personal data if you uninstall Firefox.

hello,

I had removed personal data when I uninstall Firefox.

and I cannot install again with any way, do you know how full uninstalling and install again?

I wait for your answer...

thanks a lot...

If you removed your personal data then all your profile data like bookmarks and saved passwords that is stored in the Firefox Profile Folder has been removed. So if you do not have a backup then that data is gone.

For this issue you need to remove the Firefox program folder ("C:\Program Files\Mozilla Firefox\") because some files were in use and couldn't be updated. Deleting the program folder makes it possible to write a fresh copy of all files.

See also:

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

Hello,

The Firefox program folder ("C:\Program Files\Mozilla Firefox\") I had already removed, but I see the * http://kb.mozillazine.org/Browser_will_not_start_up#XULRunner_error_after_an_update and I use in my computer "ZoneAlarm Extreme Security". I use other browser to download "Firefox" and install and now it works, but I cannot stop "Private Browsing"...

Do you know why?

I wait for your answer...

thanks a lot...

• You enter Private Browsing mode if you select: Tools > Options > Privacy > History: Firefox will: "Never Remember History"
• To see all History and Cookie settings, choose: Tools > Options > Privacy, choose the setting Firefox will: Use custom settings for history
• Uncheck: [ ] "Automatically start Firefox in a private browsing session"

thanks a lot...