Thanks Paul for reporting this bug. The problem is that there are errors when reinstalling the GRUB of your Ubuntu 12.04 in the MBR of sda:
1) update-grub returns the following error: /usr/sbin/grub-mkconfig: 1: /usr/sbin/grub-mkconfig: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found 2) grub-setup /dev/sda returns the following error: error: cannot stat /boot/grub/boot.img. 3) grub-install --recheck /dev/sda returns the following error: /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/grub-install: 1: /usr/sbin/grub-install: sed: not found /usr/sbin/: Not found. I hope a GRUB expert can interpret those errors. (FYI Boot-Repair uses the above commands via a chroot in the 12.04) ** Summary changed: - No Ubuntu or Windows boot after failed boot-repair + grub-install returns "1: /usr/sbin/grub-install: sed: not found" error ** Changed in: boot-repair Status: New => Triaged -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1007988 Title: grub-install returns "1: /usr/sbin/grub-install: sed: not found" error To manage notifications about this bug go to: https://bugs.launchpad.net/boot-repair/+bug/1007988/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs