Updating fedora 5
, and notes on specific issues you might encounter when upgrading in this way to specific EOL Fedora releases.
Upgrading Fedora using package manager contains general notes and instructions on performing upgrades using the bare package manager.
See @Joel Davis' answer for this technique as well.
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.
Generally, when going to a new version, I'll generally do a full re-install of the system.
I have found updating packages in place to be quite problematic and the amount of time spent in debugging the problems there are more complex than doing a reinstall.
Search for updating fedora 5:
Fedora Rawhide is also kind-of a rolling release, but I already knew that (and don't want to use it, if that's what you were referring to). This can lead to confused comments, such as: "distro-X is a rolling distribution if you use its development branch" — where distro-X is a standard release distribution.