Documented at <https://wiki.ubuntu.com/LucidLynx/ReleaseNotes#Boot%20options%20hidden%20by%20default%20on%20Desktop%20and%20Netbook%20CDs>:
The Ubuntu 10.04 LTS Desktop and Netbook CDs feature a new boot interface that is noninteractive by default. To configure advanced boot options, press any key at the first boot screen.
Documented at <https:/ /wiki.ubuntu. com/LucidLynx/ ReleaseNotes# Boot%20options% 20hidden% 20by%20default% 20on%20Desktop% 20and%20Netbook %20CDs>:
The Ubuntu 10.04 LTS Desktop and Netbook CDs feature a new boot interface that is noninteractive by default. To configure advanced boot options, press any key at the first boot screen.