Support Updating Android version?

view story

http://androidforums.com – When I first bought this phone, I understood that it came with Android 2.3 operating system ("Gingerbread"). But since the latest version is now 4.2, I was looking to update it, which I imagined would be as simple as updating any version of anything on my computer. I Google'd how to do it, checked my phone settings which allowed for new versions of Android to be updated and I figured that would be it. However, it never did update. I can't figure out any way to manually update and so, I am simply wondering how to do so on my AT&T Avail. Thanks! :) (General)