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I have 11.10 and Windows 7 in dual boot. Today I tried to update grub and I run the following command in terminal:
sudo fdisk -l sudo mount /dev/sda6 /mnt sudo grub-install --root-directory=/mnt /dev/sda sudo grub-install
After installation and reboot, it does not show the grub menu (from which I can choose which OS to boot) and it directly boots Ubuntu.