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I am trying to install Ubuntu 12.04 over Windows 7 using a USB drive. However, I am not able to install it. Installation breaks saying that "bootloader cannot be installed on this device." In the details section, I see the ubiquity message saying that it can't read the partition from dev/sda. I've tried various things, boot-repair one among them (, but no luck. What am I exactly doing wrong?

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Did you start with clean disks with no partition table on it or did you reuse the disks. This can be the reason why your system won't boot. Guess how I know.

First clean your disks with:

dd if=/dev/zero of=/dev/yourdev bs=512 count=1

replace yourdev with the device name of your disks

Then install Ubuntu again. It will then install new gpt partition tables. You only need a swap and a boot partition in raid ofcourse.

Don't forget to adjust your uefi settings in the bios.

Success !

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Sorry for the delay, but I was able to install it by disabling RAID. Thanks anyway!

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