Some options for installing GRUB to disk, adding a new OS to GRUB, or updating GRUB
(there are other ways, such as directly using the OS prober)
1 Boot a new OS with Super Grub2
then enter in the terminal in the booted OS:
sudo apt-get install grub
sudo grub-install /dev/sda
(where "sda" is the root of the hard disk you want to install GRUB on)
super grub2 (boots into a OS with no GRUB yet installed on the machine)
2 Add OS to the GRUB menu and set a splash screen with Grub Customizer
this is easy if there is already an OS on the machine with this programme installed
how to use http://www.howtogeek.com...
get it here https://answers.launchpad.net... (v 3.0.1 or higher)
unpack it and build with
sudo make install
This time on start there was an error message (Nov '12) so I click ignore. I found my new OS in "Trash"!
Also, clicking on Refresh sort of freezes the programme. Once you've added the OS, and any particulars, like the time out for GRUB screen, click save and then >File >write to MBR for grub to be updated (File >save only saves settings in Grub Customizer).
3 Grub Recovery CD
Run this Live CD and the Recovery app automatically searches for OS's. Open the Advanced options to choose location to install GRUB and any other particulars.
4 Chroot from a Live environment into the new OS's partiton and install GRUB,
mount /dev/sda2 /mnt
mount -t proc none /mnt/proc
mount -o bind /dev /mnt/dev
mount --bind /sys /mnt/sys
5 Using Rescue Mode of a net install CD
type "rescue" at boot prompt ? or select Advanced > Graphical Rescue Mode
when it arrives at rescue mode, select the mount point for the OS partition e.g. sda5
test the internet connection
edit /etc/apt/sources.list if necessary
apt-get install grub
Removing a non-present OS from the GRUB menu
from a booted OS run:
Read up on Grub dedoimedo.com/