Click on tools/options/advanced/update and uncheck firefox
Click the picture to make it larger..

Wow! That was so easy it's scary! Thanks, Jean, for the tip!

Jann

Wait if you mean you do not want the new version 3 of firefox you won't get that in your updates pop up you have to go to firefox site to download it.

What you are getting in your update pop up is simply the latest update to the version you currently have, this is a security update and is a needed one.

Just look at the version number it tells you it will be installing if it does not say 3 something then no worry it will not be the NEW firefox it will simply be a security update for your 2 version that you have.

Many people are getting confused about this. Just read it and see the version number. You need to continue to get your security updates for your current version number.

Yup. Add me to the list of confused.

Also, add me to the probably small group of people who don't know where to look for "the version number it tells you it will be installing" as you suggest.

Lost, lost, lost....

Jann

ok when you get a pop up from firefox saying it has an update for you it will always tell you what version it is going to be updating you to, for example this latest one that just popped up for me yesterday said it was going to install 2.0.0.16
this is a screen shot of that update notice box as you can see it tells you the version number and also has a link you can click on that tells you more details about this update.
{{gwi:1481948}}

To find the current version you have of firefox go to Help at the top then About Firefox.

Any big upgrade from like version 2 to version 3 it will not come by auto update you will have to go to the firefox download website and download it from there so you do not have to worry about that.