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I have an ASUS G75VW with UFEI. Since I bought it, it has been a pain in the ass to get Ubuntu working beside Windows. I finally made it but this week I decided it was time for a new install and after several install tries I ended up wiping my whole HDD through Gparted on a friends computer.

I started from scratch and now I have windows 8 installed properly and ubuntu installed on its own partition, but only windows boots, I was going to try a boot repair, but the pc won't boot from the ubuntu USB it throws an error: "Missing Operating System".

If its any good information, I have a 1tb HDD the first partition is Windows, the second Ubuntu, I don't know if this has something to do with the partition table being GPT, I was thinking wiping the HDD again with a Live CD and making a new partition table and then a installing windows and ubuntu.

Any help will be appreciated.


The usb live disk was corrupt, I did it several times and turn out the usb was corrupt or something.

I had to do boot-repair and on the second time, the problem was fixed.

share|improve this question
Have you tried SuperGrubDisk? – elboletaire Nov 17 '13 at 12:51
Did you check that the USB correctly boots on someone else PC? – Braiam Nov 17 '13 at 12:51

You're probably running into issues related to selecting the boot mode -- BIOS/CSM/legacy vs. EFI/UEFI. This can usually be controlled to some degree via firmware settings and/or via the firmware's built-in boot manager. Each can usually be accessed by pressing some function key (or Esc or Del) early in the boot process, but which you get (the firmware setup utility or the boot manager) depends on which key you press. Unfortunately, it's impossible to be more precise than this because these details vary between computers. (FWIW, though, my ASUS motherboard enters the firmware setup utility via Del and the boot manager via F8.)

In theory, if you prepared the Ubuntu USB drive via a dd command from the .iso image file, it should boot in either BIOS/CSM/legacy mode or in EFI/UEFI mode. In practice, though, if you used another utility (like unetbootin), all bets are off; these tools often render the resulting image unbootable in one mode or another (usually EFI/UEFI mode).

Because you're dual-booting with Windows and using GPT, it's safe to say that Windows is booting in EFI/UEFI mode. It's impossible to say about Ubuntu, though; unfortunately, Ubuntu's installer is still brain-dead when it comes to detecting mis-matched boot modes, and it will happily install in BIOS/CSM/legacy mode on a computer that has a copy of Windows that's booting in EFI/UEFI mode. This can lead to problems, including exactly the one you describe, this may be what's happened to you; however, there are other possible explanations. For instance, you might have buggy firmware that refuses to boot anything but the Windows boot loader, or you might have Secure Boot enabled and no Secure Boot support for Ubuntu. (Ubuntu theoretically supports Secure Boot, but this support sometimes fails to work.)

Thus, I recommend you do the following:

  1. Disable Secure Boot.
  2. Prepare a USB flash drive or CD-R with my rEFInd boot manager and try to boot from it.
  3. If rEFInd boots, and if it can launch both Windows and Linux, try installing rEFInd's Debian package in Ubuntu. This should take over as the default boot manager. If this works, quit; you're done. (Unless you detest rEFInd. In that case, learn about all the available EFI boot loaders and install whichever one sounds good to you.)
  4. If you boot straight to Windows when you reboot after installing rEFInd, then chances are you've got a buggy firmware. Reboot to Linux using the rEFInd USB/CD-R. You can then either:
    • Type sudo /boot/efi/EFI/refind /boot/efi/EFI/Microsoft/Boot. This implements a hack that renames rEFInd so that it looks like the Windows boot loader. The firmware should then run rEFInd.
    • Run Boot Repair, but be sure to use the Advanced settings tools and select the box to back up the Windows boot loader and put GRUB in its place. (I don't recall the exact wording of this option.) This will do something similar to, but with GRUB rather than rEFInd.
  5. If all of this fails, post the URL that Boot Repair generates. It will give us more detailed information about your computer, which is necessary to give a more specific answer to your question.

One more point: You may want to read my Web page on EFI/UEFI Linux installation. It will give you a better understanding of how these things work, which may be helpful in solving your current problem and avoiding similar problems in the future.

share|improve this answer
This is a great response. Thankfully my problem was much easier. But I will keep this in mind for future problems. – Adrian Matteo Nov 21 '13 at 13:25

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