"Many of the steps to an Ubuntu Linux server setup are either
trivial (e.g., selecting a language) or similar to the desktop
installation process (e.g., choosing a time zone or providing
information to set up a default user account). Others, however, are
very different from the Ubuntu desktop setup process, and some
require your careful attention.
"At almost every step of the server installation process, you'll
see a "go back" option on the screen. Choosing this option will not
actually take you to the previous step; it will, rather, take you
to a list of every step in the server installation process, listed
sequentially. To make matters even more confusing, selecting an
installation step from this list will not always give you the same
view as you get by sticking with the default installation screens
all the way through."