This post explains how to revert the GRUB after your Linux (Ubuntu 14.10)/Windows (7) dual-boot workstation boots directly to Windows the Windows update. This procedure is valid for non-EFI (legacy) workstations. For EFI workstations see another post.

1. Get a sysresccd boot image and boot the workstation from it.
   • Note that you cannot make an bootable USB stick using dd but executing an installation script as explained in the documentation.
   • This recipe was tested on 4.5.3.
2. Find your Linux root partiton using fdisk:
   1. fdisk /dev/sda (sdb, sdc…)
   2. p (prints the partiton table)
3. In this example we found the suspected root partition from /dev/sdb2. It has the boot flag on and the partition type is “Linux”.
4. mkdir /tmp/root
5. mount /dev/sdb2 /tmp/root
6. ls /tmp/root (make sure that this contains the root partition)
7. grub2-install –root-directory=/mnt /dev/sda
8. reboot
9. As soon as you get your Ubuntu up and running re-instal grub:
10. sudo grub-install /dev/sda