(Before everything, I'm french, so sorry for my english in advance)
I'm facing a lot of problems for installing UBUNTU 12.10 on my new laptop dell inspiron 15z 5523 (ultrabook). It seems that all my problems come from the fact that I can't boot my ubuntu liveusb in uefi mode. When I boot my liveusb in UEFI mode, I have a blank screen and nothing happens (I precise that I tried with all the following combinations : secure boot enabled/disabled / fastboot enabled/disabled).
But I'm able to boot in LEGACY mode and I did (many) installations from this mode, and use the boot repair tool to convert my intallation in UEFI mode. But if I boot the fresh installed ubuntu in uefi mode, I have a blank screen (a purple one). My conclusion is that I can't boot Ubuntu in UEFI mode either with Ubuntu installed version or Ubuntu live session. It's very annoying, because I don't see how to install a dual boot with windows 8 in UEFI mode and a Ubuntu in LEGACY mode. Here is one of my first boot repair report : http://paste.ubuntu.com/1518490/
I have also some error messages with the following packages when I apply commands asked by the boot repair : grub-efi-amd64 grub-efi
I'm hopeless. Any help is welcome !
Edit 1 - "Solution" = "do nothing" ! Solved or "bypassed", it's as you want. The fact is that UBUNTU doesn't work in UEFI mode on my DELL laptop. So I booted my live-usb in LEGACY mode and installed Ubuntu normally (with a bios_grub partition unformatted of 2 mo). Now I m able to switch OS simply switching the BIOS mode (UEFI/LEGACY) entering in the BIOS. the Bug is still there, but I have what I need. My problems came from the fact that after each installation I used the boot repair tool which deleted the access to one of my OS.