I prevented Firefox from updating altogether. I never want it to auto-update. These are the settings I have in about:config:

• app.update.auto - false
• app.update.enabled - false
• app.update.silent - false

Oh, by the way, do not trust that "Check for updates" button in the about:Firefox window. That should have been renamed to "Get updates".

All I wanted, was it to notify me & let me decide. Yeah I've turned off the update completely. I just dislike heavy-handed tactics. Yeah I discovered it was a get update button a while back. :~P I went to FF because I hated IE & also I don't trust Chrome. I want a browser that functions the way I tell it. Why is that too much to have?

Oh well... Thanks for replying.

I did the same thing, clicked on "check for updates..." now I have a new version "waiting to be applied" despite the fact I never gave permission for the update to be downloaded.

I am not happy with this, and given I have already stopped using Firefox most of the time, I may well uninstall it entirely after this.

Firefox still works well. Just never trust that "Check for Updates" button again. The first time Firefox pulled that trick, I force quitted it, and deleted the partially downloaded update file. The same thing goes for Thunderbird.

I just turned on my netbook (W7 32 bit) and it took nearly a dozen tries to get Firefox to launch. When it finally did launch, it was wonky and many of the "about:config" changes I had made were changed back to default. My home pages was also reverted back to Firefox's default search page. I eventually discovered that Firefox had updated to version 19.0.

I always keep all my PCs with auto-update disabled. I've been a PC dude for 20+ years - professionally. I know for a fact that I had updates turned off in Firefox's options. It updated anyway. I did not click any buttons that said "check updates." I remember exactly what I had done on my netbook previously and am 100% certain I had nothing to do with the update. My netbook is free from viruses and is functioning as normally as ever - except for Firefox breaking the rules.

I don't want to know how to keep Firefox from updating. I want to know why it updated regardless of my wishes and choices. Now I have to go back and turn of Flash and animated images and all that, all over again. Pain in the butt. Regardless of all that: updating should not have toggled my configs back to default!

when your preferences didn't save then it might be also true that your update specific settings didn't stick & that's why your instance auto-updated. some security software might interfere here (also when launching firefox isn't working normally). also see How to fix preferences that won't save