I just got a netbook (Dell Vostro A90N) with Hardy Heron on it and I'd like to upgrade it to the latest version of Ubuntu. Whats the quickest way to do that?
The quickest way to upgrade is to update /etc/apt/sources.list as others have suggested. However, the approved way is to upgrade to Intrepid first, then to Jaunty, following the instructions provided.
Users of Ubuntu 8.10 can upgrade to Ubuntu 9.04 by a convenient automated process. Users of older Ubuntu releases need to upgrade to Ubuntu 8.10 first, and then to 9.04. Complete instructions may be found at http://www.ubuntu.com/getubuntu/upgrading.
This should reduce the likelihood of having to troubleshoot issues arising from the upgrade.