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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 http://askubuntu.com/questions/221835/installing-ubuntu-on-a-pre-installed-uefi-supported-windows-8-system?lq=1 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.