Remove the files in the updates and updates\0 folder.

You may need to delete active-update.xml and updates.xml as well if present.

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

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

Thanks for the answer. I removed the two files. Firefox closed for a windows reboot. This morning I got a message when I opened FireFox that I needed to apply the update as soon as possible...so I did click apply now. The box said accessing Firefox update manager and it went on and on like that forever while I was using the browser perfectly fine in the foreground. I looked half an hour later, it's still trying. Once before I had this problem with Firefox update and I removed firefox from my machine and downloaded it anew. When I get time that may be the answer.

If there are problems with updating then best is to download the full version and uninstall the currently installed version.

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

• Firefox 4.0.x: http://www.mozilla.com/en-US/firefox/all.html
• Firefox 3.6.x: http://www.mozilla.com/en-US/firefox/all-older.html

• Uninstall your current Firefox version.
• Do not remove personal data when you uninstall the current version.

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.

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.

Thank you for the detail on the uninstall. I always worry about losing my collected info when making this kind of change. I'll reinstall and go from there. Thanks much.

You're welcome