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I tried to install Ubuntu 12.10 along with Windows 8 64bit from USB stick in a brand new Sony Vaio but now I get a black screen with the message :Operating system not found'. I can't get into Windows 8, neither into Ubuntu.

I saw this answer but I did it on a wrong way

I did these steps:

  • I made a partition 20 GB

  • I restarted the laptop from Settings->General->Troobleshoot->UEFI settings->

  • I selected 'boot from USB'

    and then installed Ubuntu 12.10. Installation went OK until I was asked to restart computer. I did so, and I had 4 choices (Ubuntu, Windows recovery or something like that, Windows 8, System (I don't really remember exactly)).

  • I selected Ubuntu but I got a flashing screen

  • I tried Windows 8 but didn't work

  • Then I selected System and got into BIOS

  • I disabled the Secure boot, and also turned the UEFI mode to Legacy.

  • saved the changes, After that I got a black screen with the message "Operating system not found". Whatever I type I get the same message. I can't get into Windows, neither in Ubuntu. What can I do; I think I have to get back into BIOS but don't know how.

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marked as duplicate by Luis Alvarado, Jorge Castro, Nathan Osman, Eric Carvalho, belacqua Feb 14 '13 at 0:36

This question was marked as an exact duplicate of an existing question.

Sometimes we just have to read the manual. Vaio has an ASSIST button on keyboard, so when I pressed it when laptop was turned off, the Vaio care resque mode opened and I changed everything I had changed before. Now I can get into Windows 8 but not into Ubuntu. – Evi Feb 12 '13 at 17:29

I have two suggestions:

  • You can try the Ubuntu Boot Repair tool. This might get Ubuntu booting. If it does, though, it may rename the Windows boot loader in a way that could cause further problems down the road. On the plus side, it's fairly easy to use this method now.
  • You can install my rEFInd boot manager:

    1. Download the USB flash drive image or CD image and transfer it to the appropriate medium.
    2. Take note of your Linux root partition number. It will probably be 5 or above. You may need to use a Linux emergency disc to discover this information.
    3. Boot from the rEFInd medium.
    4. In rEFInd, highlight one of the Linux options that refers to a Linux kernel (vmlinuz-*).
    5. Press F2 or Insert twice. This should open a line editor on your Linux options.
    6. Add ro root=/dev/sda5 to the options, changing /dev/sda5 to whatever your Linux root partition's identifier is.
    7. Press enter. Linux should boot.
    8. Download and install the rEFInd Debian package.

    Thereafter, you should be able to boot Linux via rEFInd, bypassing GRUB, and without adding your root device specification manually. You can optionally clean things up by uninstalling GRUB and editing rEFInd's refind.conf file to suit your needs.

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