I have a Samsung laptop NP350E7C. It comes with Windows 8 and I'm trying to install Ubuntu 13.04. The first time I installed it with the live USB, it worked, but windows stopped working. I repaired windows and now there is not way to reboot on Ubuntu. I even tried to use windows' boot manager instead of GRUB2 with no success.
I then followed the instructions at http://doc.ubuntu-fr.org/uefi?redirect=1 (disabled fastboot and secureboot in the BIOS) and re-installed ubuntu. I then had the windows blue screen as predicted by this tutorial and I could repair it with the instructions from their link.
Than, I needed to repair ubuntu's boot with boot-repair. Using the recommended options, I always get to this error:
An error occurred during the repair.
Locked-ESP detected. You may want to retry after creating a /boot/efi partition (FAT32, 100MB~250MB, start of the disk, boot flag). This can be performed via tools such as gParted. Then select this partition via the [Separate /boot/efi partition:] option of [Boot Repair].
According to this thread http://ubuntuforums.org/showthread.php?t=2112273 the problem is that the file /EFI/ubuntu/grubx64.efi is corrupted and then if we can remove it and run boot repair again, everything should work fine. I then removed the file using the instructions at How can I remove Ubuntu from the UEFI boot options? but every time, I run boot repair I still get the same error.
My logs are at http://paste.ubuntu.com/6081052/
Any help is very appreciated. Thanks again