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I'm trying to boot Ubuntu 13.04 and Windows 8 on my aspire S7. I have two SSDs and I installed Ubuntu first on one then Windows 8 on the other after a while.

I can boot into either OS by entering the BIOS settings and changing the boot drive but I would rather have GRUB do the boot selection.

I've tried running

sudo update-grub

but that doesn't find Windows at all.

If I run

$ sudo grub-install /dev/sdaBootCurrent: 0003
Timeout: 2 seconds
BootOrder: 0003,0002,0001
Boot0001* Windows Boot Manager
Boot0002* HDD0: 
Boot0003* HDD0: 
BootCurrent: 0003
Timeout: 2 seconds
BootOrder: 0000,0003,0002,0001
Boot0001* Windows Boot Manager
Boot0002* HDD0: 
Boot0003* HDD0: 
Boot0000* ubuntu
Installation finished. No error reported.

Which seems to pick up windows, but there is still no grub entry.

Any ideas how to get GRUB to give me the option when I boot?

share|improve this question
up vote 1 down vote accepted

Grub2's os-prober does not work with UEFI. Bug report shows they just released a fix, but I do not think it is in any current version. grub2's os-prober creates wrong style (BIOS) chain boot entry

When you installed Ubuntu did you install in UEFI mode? And when you installed Windows did you install in UEFI mode? And do both gpt partitioned drives have an efi partition?

May have to manually edit UUID of efi partition, but Boot-Repair updated for two drive installs. You may need to chain load to the other efi partition not the usual entry to the same efi partition.

Post the link to the BootInfo report that this creates. Is part of Boot-Repair:

Boot Repair -Also handles LVM, GPT, separate /boot and UEFI dual boot.:

You can repair many boot issues with this or 'Create BootInfo' report (Other Options) & post the link it creates, so we can see your exact configuration and diagnose advanced problems.

share|improve this answer
Both installs are in UEFI mode and I believe they are both GPT partitioned drives with an EFI partition. A link to Boot-Info However, Boot-Repair fixed my problem and Windows 8 now shows up in the GRUB menu. Thanks! – EmbMicro Aug 2 '13 at 12:59
Windows installed its efi boot files into the efi partition on your Ubuntu drive. I am a bit surprised that you only have then one NTFS partition on sdb. Windows supposedly needs other partitions. Microsoft suggested partitions including reserved partition for gpt & UEFI: Older Windows info on gpt - 2008 updated 2011: – oldfred Aug 2 '13 at 17:15

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