There is nothing that says you can't use software after it is no longer supported, that is your decision. The problem is that since the Internet is in constant flux and things are regularly changed, it is possible that 3.6.17 might, some day, not be able to correctly function with changes to the internet. If the version you are using is no longer supported, you can't get official help or expect them to fix bugs. I've seen hundreds of people complaining about the Firefox 4 and I've also been involved with the Mozilla bug reporting forum and other forums and I have gotten the very clear impression - sometimes it has been directly stated - that the people working on Firefox know what is best for everyone and they aren't going to listen to complains about new features and "looks" and that everything they change is an improvement and - so there! This is exactly the attitude that is doing so much harm to Microsoft. "WE KNOW how people should use the computer and Windows 7 is vastly superior to Windows XP" - for example, and it is not true. Many of the new features in Windows 7 are steps backwards from features that worked better in XP. Too often Microsoft (and now Mozilla) changes things simply because they can or because they think that their view is the only valid view. From what I've read, I don't want to upgrade to Firefox 4 and should Firefox 3.? "break" in the future, I'll go to another browser and use it until it gets improved beyond usability. I believable that Firefox 4 should have been brought out as another product - not an upgrade to Firefox 3. I've been in Data Processing (deep, heavy, multifaceted experience) for 37+ years and I consider it a mortal sin to change a user interface unless that change is absoletly necessary. Not just because it would be "neat" to change it but only if it has to be changed to continue to work properly. The programmers today think that "neat" and "sexy" trump function and usability., They think that if a user can't figure out how to use a new version of software, that is their fault, not the programmers' I could rant on this subject for hours - I give talks on it regularly - suffice to say that a culture has developed that puts "neat" and "sexy" above function and usability and unless we can eliminate it, we will continue to see new "releases" of software which don't look or work like the previous release of the same software. Stan