Disable 12.10 Ubuntu GUI Boot

In /etc/default/grub, change this line

GRUB_CMDLINE_LINUX_DEFAULT="splash quiet"

to

GRUB_CMDLINE_LINUX_DEFAULT="text"

Run

sudo update-grub

when done. This is easily reversed too if you need to change back.

Grub Customizer is a GUI configuration tool to allow users to change the Grub 2 settings without using the command line. The application allows the user to add, remove, freeze, rename and reorder boot menu items. It will also allow changes to the Grub 2 configuration settings such as background image and menu timeout. For long-time users familiar with StartUp-Manager, this application performs many of the same capabilities with additional options. It also makes convoluted guides such as my “Grub 2 Title Tweaks” unnecessary for all but the most devoted command-line enthusiasts!

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer

Also have a look here

http://debianhelp.wordpress.com/2012/09/30/to-do-list-after-installing-ubuntu-12-10-aka-quantal-quetzal/