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I just reinstalled Ubuntu 12.04 using a LiveCD mounted on a USB drive. When the USB drive isn't plugged in... things won't boot. I'm new to Ubuntu, so please bear with me. After a bit of reading I see that GRUB needs to be fixed/ updated along with the MBR. Unfortunately, I'm not sure how to go about this. When booting with the USB stick plugged in, I get a menu that displays the different boot options and I can boot in to either Ubuntu or Windows 7 like I should be able to. I also have the LiveCD USB stick listed as the first device accessed during the boot sequence. This thread seems to have a good walkthrough but I'm stuck on the first step.

When running ls, I see: (hd0), (hd0,msdos6), (hd0,msdos5), (hd0,msdos3), (hd0,msdos2), I think. This is from memory.

Starting the first step with ls (hd0,msdos6) returns Bad filename and ls (hd0,msdos5) etc returns error: unknown filesystem.

It would seem that msdos6 is the Ubuntu partition. But I can't access it. Any suggestions would be appreciated.

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Assuming that the main drive is /dev/sda, I would use

sudo grub-mkconfig -o /boot/grub/grub.cfg
sudo grub-install /dev/sda

To (re)install it.

share|improve this answer
is there a way to verify that? that the main drive is /dev/sda I mean. – Jason Jul 14 '13 at 21:12
Type sudo fdisk -l to list all available drives (lines beggining with "Disk *****:"). In most common installations, there's only one :) – John WH Smith Jul 14 '13 at 21:17
ok. better question... will doing this potentially mess everything up? :) – Jason Jul 14 '13 at 21:35
The -l option means "list". You'll just get some output :) – John WH Smith Jul 14 '13 at 21:36
sounds good. thank you. i'll report back in after I try it out. – Jason Jul 14 '13 at 21:46

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