Which security software (firewall, anti-virus) do you have?

Some security software has virtualization or sandbox features that may cause problems by protecting and restoring files.

If files already have been downloaded then remove the files in the updates and updates\0 folder. You can also delete active-update.xml and possibly updates.xml (this will clear the update history).

• http://kb.mozillazine.org/Updates_reported_when_running_newest_version
• http://kb.mozillazine.org/Software_Update (Software Update not working properly)

C:\Users\<user>\AppData\Local\Mozilla\Firefox\Mozilla Firefox\updates
(%LOCALAPPDATA%\Mozilla\Firefox\Mozilla Firefox)

Do a clean reinstall and delete the Firefox program folder before (re)installing a fresh copy of the current Firefox release.

Download a fresh Firefox copy and save the file to the desktop.

• Firefox 20.0.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.

Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.

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

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

Ok, I think that I have fixed this for now. I have not tried to restart the computer yet, but I have had an update that stuck so far.

My suggestion for anyone else who has this happen, is to save all your prefs and stuff in a file you copy to another drive. Once that is done, completely remove firefox, I mean everything. Once you have restarted twice, then install the version you want to use. I have decided to go with the beta 21.0.0, but that is up to you.

One thing that is a must: MAKE SURE you REMOVE the firefox maintenance program and folders, this harbors some sort of problem. When you reinstall Firefox, use custom install, and uncheck that before installing. Don't know why it should matter, but it does.

After re-installing then before starting restore your prefs, etc. or your profile if you will. This seems to work. As dumb as it sounds, there seems to be a problem with the maintenance service.

I want to thank all of you who gave me ideas. I think I used some combo of many oh the ideas, by picking and choosing among them, it finally worked. I hope that this whole thread may help someone else. So once again THANK you all for your help.

Note that by using one of the Beta builds of 21.0 you will be on the Beta channel and will get Beta updates including 22.0 b1 after 21.0 is released in about ten days. To get back on Release channel it may be easiest to install the 21.0 when it is released.

I am aware that I am in the beta channel, however the release channel is what screwed my firefox up to begin with.

My advise to anyone with these kinds of issues is to do what I suggested above and go to beta channel. As sad as it is, the beta channel seems to be more stable that the release channel. That may not be the case for everyone, but I am just relating my experience.

I would not like to be seen to discourage use of Firefox beta I am all for more people installing and trying it. There are however a couple of things anyone using Beta may wish to consider.

1. Backups
   Keep your bookmarks backedup, and maybe also your profile. If you have a second device and that is synced the second device is an effective backup. Beta is by nature slightly less reliable and less stable than the Release, so backups are even more important.
2. Multiple installs
   You could as a custom install have Firefox Release, and Firefox Beta both installed.
   • Profiles
     You should then ensure each Firefox version has a separate profile.
   • If Beta ever gives problems, you may be fairly certain that falling back to using the Release version will work, because that is then a version that you will have been previously using without problems whilst it was on the Beta channel. Having both channels installed means it is very easy to revert.