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I have tried a live CD for both 12.10 and 13.04 and done the install alongside Windows 7 option. It gets to the point it asks me where to install and the ONLY option in the drop down is my WD Passport external drive. I have not created a partition on my internal drive. Either way, Ubuntu completes the install, and reboots. Immediately Windows 7 loads, no option to boot to Ubuntu to try it out. If I go into the boot options by using F8, I can change boot device and my external drive shows twice. If I select the one, I get a GRUB prompt that says it can not boot. If I select the other (SES) then it starts into Windows 7 right away (Windows is not installed on that drive, although there is a partition there for backup files). Is Ubuntu unable to boot from an external device? Would seem odd since a flash drive or CD both work. Or do I need to create a partition on my internal main drive to allow Ubuntu to dual boot?

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How many bootable devices show up in your BIOS? – Brandon Bertelsen Apr 27 '13 at 1:38

This is probably a /etc/fstab problem.

You have to reboot with the live CD, mount the external disk (where you installed Ubuntu), and check the /etc/fstab file that resides on that external disk.

You have to edit /etc/fstab to make sure that when you boot from the external disk, the root of your filesystem is mounted on that bootable disk (probably /dev/sdb1).


Then you have probably another problem. GRUB sets root on (hd0,0), the first disk, first partition. (but that is the sda-disk, first partition).

So GRUB must set root on the second disk,first partition, that is (hd1,0) Still running the live CD, you have to run grub-installer.


Afterwards, check your /boot/grub/grub.cfg file.

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