If using Zone Alarm's browser virtualization or any other similar product or a sand-boxing program (i.e., Sandboxie), turn it off when updating Firefox or Firefox Add-ons. You can post on the forum for any such product that you might be using to get other instructions on the proper use of the product. The updater wasn't able to update all the files and some were left as older versions. Do a clean reinstall. See: [http://kb.mozillazine.org/Browser_will_not_start_up#XULRunner_error_after_an_update Browser will not start up - XUL Runner error after an update] #Download a fresh Firefox copy and save the file to the desktop. #*Firefox 7: http://www.mozilla.com/en-US/firefox/all.html #Uninstall your current Firefox version. #*'''''Do not remove personal data when you uninstall the current version''''' #*Your bookmarks and other profile data are stored elsewhere in the Firefox Profile 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. #*See [http://support.mozilla.com/en-US/kb/uninstalling+Firefox Uninstalling Firefox] '''''and''''' [http://kb.mozillazine.org/Uninstalling_firefox Uninstalling Firefox (Mozillazine)] #*Also see: [http://support.mozilla.com/en-US/kb/Backing+up+your+information Backing up your information] '''''and''''' [http://kb.mozillazine.org/Profile_backup Profile backup (Mozillazine)] #Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer. #*It is important to delete the Firefox program folder/directory to remove all the files and make sure that there are no problems with files that were leftover after uninstalling. #*See: http://kb.mozillazine.org/Installation_directory #Install the fresh copy of Firefox that you downloaded in step 1 '''If this reply solves your problem, please click "Solved It" next to this reply when <u>signed-in</u> to the forum.''' ------------------------- Not related to your question, but... You may need to update some plug-ins. Check your plug-ins and update as necessary: *Plug-in check: https://www-trunk.stage.mozilla.com/en-US/plugincheck/ *Adobe Shockwave for Director Netscape plug-in: [https://support.mozilla.com/en-US/kb/Using%20the%20Shockwave%20plugin%20with%20Firefox#w_installing-shockwave Installing ('''''or Updating''''') the Shockwave plugin with Firefox] *Adobe PDF Plug-In For Firefox and Netscape: [https://support.mozilla.com/en-US/kb/Using%20the%20Adobe%20Reader%20plugin%20with%20Firefox#w_installing-and-updating-adobe-reader Installing/Updating Adobe Reader in Firefox] *Shockwave Flash (Adobe Flash or Flash): [https://support.mozilla.com/en-US/kb/Managing%20the%20Flash%20plugin#w_updating-flash Updating Flash in Firefox] *Next Generation Java Plug-in for Mozilla browsers: [https://support.mozilla.com/en-US/kb/Using%20the%20Java%20plugin%20with%20Firefox#w_installing-or-updating-java Installing or Updating Java in Firefox]

I had already uninstalled, rebooted, and installed clean. No combination of removal and installation seems to take care of the problem...

Which security software (firewall, anti-virus) do you have? Did you remove or rename the Firefox program folder (C:\Program Files\Mozilla Firefox\) to remove any leftover files?<br /> You may need to reboot the computer

I have Zone Alarm, but I don't have the toolbar installed. I downloaded the new Firefox and installed it off-line. I also removed the Firefox directory and it still didn't work. As far as re-booting, I've done that plenty of times... Clean boot. Remove software. Clean Reboot. Install software. Clean Reboot. Still doesn't work. Tried that multiple times now after initially trying the upgrade version a few times failed. Getting frustrated...

If you use ZoneAlarm Extreme Security then try to disable Virtualization. *http://kb.mozillazine.org/Browser_will_not_start_up#XULRunner_error_after_an_update See: *[[/questions/869951]] *[[/questions/869812]] *[[/questions/880170]]

clearing the ZoneAlarm virtual cache (depending on ZA version, go to "Browser Security -> Settings -> Advanced" or "Internet -> Web Security -> Settings") then click "Clear Virtual Data" That part worked! THANK YOU! Now, I was able to fully update my Firefox! Thanks again! I was not able to find that info on my own.