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I'm trying to install Ubuntu 13.04 alongside Windows 8 (to dual boot) on my new laptop.

Since there is already an EFI partition on the disk, I didn't create another one (as suggested in: https://help.ubuntu.com/community/UEFI#Creating_an_EFI_partition) and I selected /dev/sda3 as the device for boot loader installation. After the installation, ubuntu worked fine but I couldn't boot into Windows 8 (when I select the win8 in Grub screen it gives an error message). I restored computer to factory state using recovery and now trying to install ubuntu again.

Which partition should I choose for "Device for boot loader installation"? Thanks for the answers.

Harddisk is partitoned like this:

enter image description here

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marked as duplicate by Alvar, NikTh, Jorge Castro, Eliah Kagan, AgentCool Jul 31 '13 at 3:34

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1 Answer 1

While with BIOS/MBR systems you install to the MBR and almost never to a partition, with UEFI you always install to the efi partition. It actually should default to install to that partition anyway and you can only have one efi partition (with boot flag) per drive.

In your case installing grub to sda3 the efi partition is correct. You should see multiple folders for each system you have installed, in Ubuntu they are mounted at /boot/efi and on the drive you have ubuntu & Microsoft folders with boot files:

/boot/efi/EFI/ubuntu/grubx64.efi /boot/efi/EFI/Microsoft/Boot/bootmgfw.efi

Grub2's os-prober has a bug and only creates BIOS boot entries which do not work with UEFI. You do not chainload to the Windows install like BIOS, but chain load to the efi partition. Boot-Repair can automatically create entries in 25_custom or you can manually add entries as shown in bug report to your 40_custom.

grub2's os-prober creates wrong style (BIOS) chain boot entry https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1024383 type of entry from Boot-Repair that should work. menuentry "Windows UEFI bkpbootmgfw.efi" { menuentry "Windows Boot UEFI loader" { Type of entry that does not work: 'Windows ...) (on /dev/sdXY)' Some info in Post #3 on cleaning up menus, if desired. http://ubuntuforums.org/showthread.php?t=2085530

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