Additionally having maintained RHEL, Fedora & Cent OS systems for over the past decade, I would never even consider using this method for anything. So typically people would do one of the following: Use the Rawhide release, which is the bleeding edge version, similar to how Sid is in Debian.
Having tried this method on numerous occasions I would not consider this to be on par with the available in the Debian/Ubuntu distros which actually worked very well.Before you do anything, you will want to make sure you have the latest packages for Fedora 22 before beginning the upgrade process.Additionally, make sure you back up your system before proceeding. Now, the message has disappeared, and I cannot find it, not any software it might have been connected with. In Gnome 3, go to activities and do a search for "software update" (or find it in your list of applications). I would suggest changing title of this question so that it better matched the question which is being concerned specifically with upgrading from one release to another. I dismissed it, as the only option it had presented me with was "Install updates", and I wasn't quite sure what would that do. But, there is a GUI software manager, if you'd like to use it.As part of your installation of Fedora Core 5, you might wish to include the livna and the freshrpms repositories.