I've no idea how it's happened but you've managed to 'reset' Firefox. (When you actually intend to do that, the route is Help > Troubleshooting Information > Reset Firefox). That effectively reinstalls the program, while retaining things like your bookmarks.
You can delete that folder on your desktop. You can also ignore the fact that Java Console is disabled (you don't need it and it has a nasty habit of messing things up). I'd also not bother about the other things which are disabled. (AVG Security Toolbar is incompatible with Firefox 18 and it's a total pain in the @rse anyway).
You seem to have been using more toolbars than you really need so, unless they're essential to you, I'd forget about them too. That doesn't leave you many things to reinstall (which, unfortunately, is what you'll now need to do), particularly if you settle on just one extension for each purpose. (I'd recommend using Ant Video Downloader, rather than either of the two extensions you've been using, as it can download videos from lots of sites other than just Youtube).
Chris