How to update Ubuntu from Warty Warthog release to Hoary Hedgehog

From ArticleWorld

Normally, updating an operating system can be done by simply installing the new version over the old one. However, most Linux systems can do this without requiring you to download the new CD image, boot from it and follow a regular install procedure. Since all the settings are already configured, you can take the easy way when updating.

Steps

1. The first thing that has to be done is to change the repositories that are used to install packages. To do this, log in as root and open /etc/apt/sources.list with a text editor. Remove all the # symbols placed in front of lines starting with 'deb', and change every occurrence of "warty" to "hoary". Save the changes.

2. Also as root (or using sudo as a regular user) run:

apt-get update
apt-get dist-update

3. The later will ask you to confirm that you want to install the selected packages (it automatically selects the packages required for the update). If this is what you want, confirm it by pressing Y. You can still cancel the update at this point by pressing N.

4. The update will be carried on. It involves a rather lengthy download and may take a while, but you can still use your computer while the packages are being downloaded.

Notes

Should the update fail, you can ask questions in your local user group, in any Ubuntu-related forum or in the #ubuntu IRC channel on Freenode.