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I've installed ubuntu using live CD. But when I turn my computer on, it starts windows 7 instead of giving me right to make a decision, which OS I need to boot. I think I have some problems with GRUB - it isn't run.

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Try Boot-Repair – Mitch Jul 5 '12 at 17:53

If you installed using a USB then try booting with the USB connected, if you see grub and can boot Ubuntu then have a look at this guide on our website for details of how to resolve the problem. :o)

Let us know if it helps.

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Grub organises two OSs on one Harddrive, you seem to have W7 in the harddrive and Ubuntu on a CD - so tell your BIOS to boot from CD.

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Step 1 - From a Ubuntu Live CD

Open up a Terminal by hitting Ctrl Alt T; we'll run a few commands.

First, identify which is the Ubuntu partition:

sudo fdisk -l | grep -iR linux | grep -viR swap

This should return a line like the following:

/dev/sda1   *          63    77144129    38572033+  83  Linux
  • In this example, the partition identifier is /dev/sda1.

Mount this partition.

sudo mount /dev/sda1 /mnt
  • Replace /dev/sda1 with the partition identifier you identified earlier.

Reinstall Grub.

sudo grub-install --root-directory=/mnt /dev/sda
  • Replace /dev/sda with the appropriate hard drive identifier. This is the Ubuntu partition's identifier, without the trailing number.

Reboot your computer, this time without the Live CD.

Step 2 - From the installed Ubuntu

If all went well in the previous step, you should now be logged into Ubuntu.

Once again, open up Terminal by hitting Ctrl Alt T.

Now, run this:

sudo update-grub

This should detect your Windows installation and automatically add it to the Grub menu.

You're done!


To make the Grub menu show up if it doesn't by default, hold the left Shift key during the boot-up process. You'll then be able to select which OS you'd like to boot into.

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Use Boot-Repair's Recommended Repair to reinstall GRUB in 1 click. It will also provide a BootInfo summary if you need more help.

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