Questions about: menu

Here is my /etc/default/grub: # If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub. cfg. GRUB_DEFAULT=0 GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev