From Google, and the various Linux community forums, this is a fairly common problem so, in an effort to be more useful than those who simply post a link to the GRUB man page, or an article which spells out how dumb it is to install Windows AFTER Ubuntu – I thought I’d drop my experience and the resolution here – I’m bound to need it at some point in the future.
- Boot from a Ubuntu LIVE CD/USB
- From a terminal, enter the following
sudo fdisk -l
- This will identify the device / drive. For me (and most users) this will tend to be /dev/sda
- If you are still uncertain you can also run sudo blkid for more details and review the partition labels & sizes
- Mount the Ubuntu boot partition
sudo mount /dev/sdXY /mnt
e.g. sudo mount /dev/sda1 /mnt
- Run grub-install as below to drop the GRUB2 files back onto the boot partition where they should reside
sudo grub-install --root-directory=/mnt /dev/sdX
e.g. sudo grub-install --root-directory=/mnt /dev/sda
- Reboot (into your freshly resurrected Ubuntu installation)
- Open a terminal and refresh the GRUB2 menu with:
- That’s it.. you SHOULD now have both Ubuntu and Windows 7 detected at boot and be able to choose between them.
Thanks to the Ubuntu Community for this page – and all the others which pointed to different solutions and variants of this fix. If the above doesn’t work for you, Google is your friend – there’s a heap more articles out there which should offer you an eventual solution.