Hello. I'm running a dual-boot with Windows 7 and Linux Mint Debian.
My firefox version is 3.6.8
If from my firefox browser I go to Help/CheckforUpdates, I get the following message:

"Unable to Update"
A recommended security and stability update is available, but you do not have the system permissions required to install it. . .

does anyone know of a how-to as to how to manually upgrade my firefox to the latest version (including how to purge the existing version from my system)? Thanks for the help.

Welcome to the forums!

In Linux, we do not typically upgrade our applications one-by-one (this is what I call "the Windows Way"). Instead, we use an "update manager" (or terminal commands such as "apt-get upgrade") to upgrade all applications at once.

I am not familiar with Linux Mint Debian, but I recommend reading the documentation/help pages/wiki/forums for the distro to see what is the recommended update procedure.

you can try starting firefox as super user and then updating.
If not you can try going on the mozllas site and downloading the tar.gz file and then find a simply file named firefox wich is about 3.8kb in size and it will ask you wether you want to display and etc or run .. you want to run it
that is what will get you to your update firefox
you can put it in your desktop or quick launch.. or ..whatever it is called...

Duplicate thread reported. First is http://www.linuxquestions.org/questi...-linux-843989/

Thanks for the help guys. I just went to my terminal, logged in as superuser, and ran firefox. (which was in the /opt/firefox directory)
Then when I went to Help/Check for Updates, it found the update and downloaded it. From there, I exited out of my browser and restarted it. At first I was upset because the version of firefox hadn't changed! Then I noticed that when I went to Help Menu, "Check for Updates" had changed to "Install Downloaded Updates". I clicked on this and the updates were installed. I then chose to restart firefox and, when I checked the version, it was the latest and greatest. The key to the whole thing is to be in superuser mode before invoking firefox.

Browsing the web as superuser? Not smart! This is a huge security risk. Please read the Mint documentation and learn about package management and the update manager.