Have you tried to uninstall, remove preferences from your personal directory and then install the new version using its installer? Maybe there is something wrong during the update process.

Also you can check https://support.mozilla.com/en-US/kb/Firefox+will+not+start

thanks for the reply. I checked the link but it was no help.

When i google this problem. I was reading other users mention to delete the update folder within' the local settings for Mozilla and install over the top ?

I have uninstalled Mozilla in the past but i always get the same problems when updates come around. It doesn't like to update at all. At the moment firefox keeps shutting itself down with the update not finishing.

I am still having no luck, it's driving me nuts at the moment. Anyone got any ideas ?

Sorry for the replies but i am dying to get FF back up and running again.

Your above posted system details show outdated plugin(s) with known security and stability risks.

• Next Generation Java Plug-in 1.6.0_17 for Mozilla browsers

Update the Java plugin to the latest version.

• http://java.sun.com/javase/downloads/index.jsp (Java Platform: Download JRE)

Your user agent shows that you are using Firefox 3.6.9 and that the update has been successful.

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.9) Gecko/20100824 Firefox/3.6.9 ( .NET CLR 3.5.30729)

If you keep having problems then do a clean reinstall of the Firefox 3.6.9 version
See also See http://kb.mozillazine.org/Software_Update (Software Update not working properly) Remove the files in the updates and updates\0 folder:

C:\Documents and Settings\<user>\Local Settings\Application Data\Mozilla\Firefox\Mozilla Firefox\updates
(%USERPROFILE%\Local Settings\Application Data\Mozilla\Firefox\Mozilla Firefox\updates)
C:\Program Files\Mozilla Firefox\updates

You can do a clean reinstall and download a fresh Firefox copy from http://www.mozilla.com/firefox/all.html and save the file to the desktop.

Uninstall your current Firefox version and remove the Firefox program folder before installing that 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.

You can skip the step to create a new profile, that is not necessary for this issue.

See http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Clean_reinstall

I am at work at the moment which is a XP machine and my home PC is windows 7 64 pc.

The update is failing on my home system not my pc at work.

just to point out like i mention in my first post.

I did a fresh install over the top with 3.6.9 on my windows 7 system and it didn't work. I can't get firefox to work at all to use without it crashing and telling me to restart my system.

How to fix this problem in Windows 7 is

You need to delete the following folders...

C:\Users\AppData\Local\Mozilla

C:\Program Files (x86)\Mozilla Firefox

Make sure you uninstalled mozilla from you're add/remove programs also.

And then install the 3.6.9 again.

You don't lose any data like bookmarks or add on's.

Works fine again... simples.

Mozilla you need to update your help file to how to get Firefox working again as the following links where useless to window 7 users on here. No offence. But i google it, and found the information within 5 minutes after a day sitting on here hoping someone would have the answer.