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I have a samsung laptop with windows 8 single language pre installed and since it was bugging so much I decided to dual boot with ubuntu following this guide :

I was able to install ubuntu, and could load both from ubuntu boot loader. I had an issue where in my BIOS, in my boot priority ALL entries were gone except ubuntu. Then second issue, I couldn't load windows boot manager even after following the guide. So i tried playing with the easyBCD and I screwed up by deleting all entries in windows boot manager. Now, even on ubuntu boot loader, I can't load windows. On the ubuntu boot loader i see about 5-8 entries, 3-4 of them from ubuntu and the rest is some *x64.efi and recovery boots. I tried all of them and couldn't load windows. Either File is not found or when i go in windows boot manager, no operating system detected. I don't know what to do, I can't have access to my windows 8 any help please? Note that i could boot windows 8 from ubuntu loader by pressing enter on some **x64.efi but couldn't since I played with easyBCD. Here is a paste of boot repair i just did

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  1. Try re-booting with the live-CD (USB) from your installed Ubuntu distro.

  2. Don't change the partition table that exists on your harddisk. Don't wipe it out!!! Keep it.

  3. Reinstall Ubuntu - use exactly the same partitions that you used the first time to install Ubuntu in.

  4. During this install choose to install the GRUBbootloader in the Masterbootrecord of your harddisk. This will overwrite the Windows bootloader.

  5. Reboot. Grub should be able to see Windows.

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These instructions might work on a BIOS-based computer, but they won't work on an EFI-based computer, which Chris clearly has. – Rod Smith May 2 '13 at 16:28
Chris didn't said it did not work. He said, verbatim quote :"I was able to install ubuntu, and could load both from ubuntu boot loader." So? I bring Chris back to the end of step B of the installation plan that he links. If you would have read that documentation, you would agree. – user85164 May 2 '13 at 16:48
You've referred to installing GRUB to the MBR of the disk, but on an EFI-based computer, the boot loader does not go to the MBR. The Boot Repair output that Chris posted clearly indicates that he's using an EFI-based computer; there's no boot loader (GRUB, or Windows) installed to the MBR, contrary to what you've indicated. – Rod Smith May 2 '13 at 16:57

First, you should be aware that recent Samsung laptops have a known EFI bug that can brick the computer, requiring it to be returned to Samsung for repair. This bug can be triggered in any OS, including Windows. Thus, it's best to completely wipe the hard disk and re-install both Windows and Linux in BIOS mode. That's extremely awkward, though, and there have been some recent Linux kernel patches that make it unlikely that the bug will be triggered in Linux -- if you're running the relevant code. Unfortunately, I don't happen to know precisely which kernels have this fix, so I'm not sure which kernels are safe and which ones aren't. In the absence of that information, you should run the latest kernel available and hope for the best or reconfigure everything to boot in BIOS mode. I'll proceed with the assumption that you're running a safe kernel and are willing to take the risk of bricking your computer from Windows.

Based on the Boot Info Script output you've posted, the GRUB 2 entry entitled "Windows UEFI bkpbootmgfw.efi" should work; however, GRUB 2 is extremely finicky about chainloading to other EFI boot loaders. Sometimes an entry that should work doesn't work, or will work only on some computers. Therefore, I recommend you try the following:

  1. Launch Boot Repair.
  2. Click "Advanced Options."
  3. Select the "Main Options" tab.
  4. Select "Restore EFI Backups". The "Backup and Rename EFI Files" option should automatically uncheck. If it doesn't, uncheck it yourself.
  5. Click Apply.
  6. In your regular Debian installation (not an emergency/live disc), download the Debian-package version of my rEFInd boot manager.
  7. Install the rEFInd package.
  8. Reboot. Instead of GRUB, rEFInd should appear. It should let you boot Windows, GRUB (which should appear with an Ubuntu icon, and chainload to Linux), or Linux (which will probably appear as one or more penguin icons).

Assuming this all goes smoothly, you can then customize rEFInd in various ways. Chances are you'll have some redundant entries in rEFInd's menu, for instance; or you may want to tweak its appearance or change its options. The rEFInd documentation describes how to do this.

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Chris told us that the GRUB2 loader DID work. You start with the assumption that it didn't work. Why? – user85164 May 2 '13 at 16:59
At one time, yes, but not any more. In my experience, it's easier to replace a broken GRUB 2 with something else than to try to fix GRUB 2. – Rod Smith May 2 '13 at 17:02
You sure the best option is to install a new boot loader? What i know right now is that my windows 8 boot files are deleted. I will try your solution and get back to you! Thanks. – Chris Emmanuel Wong May 2 '13 at 18:01
GRUB2loader works by the way, to load ubuntu, what doesn't work is windows 8. Boot files missing and i don't know how to restore them. – Chris Emmanuel Wong May 2 '13 at 18:04
The Boot Repair output you posted indicates that you've got files with the correct names to be Windows boot files in the ESP; however, it could be that your version of Windows is flaking out because of the renaming that Boot Repair did. (Following my procedure will undo those changes.) There could also be problems on the Windows partition itself, perhaps because of what you did with EasyBCD. Such problems, if present, would be better dealt with on a Windows forum than here. As a first pass, though, you could try running a Windows recovery utility. – Rod Smith May 2 '13 at 19:42

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