sudo fdisk -lsudo mount /dev/sdaX /mntsudo grub-install --root-directory=/mnt/ /dev/sdasudo update-grub
sudo grub-install --root-directory=/mnt/ /dev/sda
/usr/sbin/grub-setup: warn: Sector 32 is already in use by FlexNet; avoiding it. This software may cause boot or other problems in future. Please ask its authors not to store data in the boot track./usr/sbin/grub-setup: warn: Sector 33 is already in use by FlexNet; avoiding it. This software may cause boot or other problems in future. Please ask its authors not to store data in the boot track.Installation finished. No error reported.
sudo update-grub
/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).
sudo grub-install --root-directory=/mnt /dev/sda
http://liveusb.info/dotclear/index.php?pages/install