I installed Ubuntu alongside Windows but GRUB doesn't show up during boot and Windows starts instead.

I used a liveCD and followed these instructions on the Ubuntu help wiki, but they didn't help.

I use the standard Windows 7 bootloader. Windows came preinstalled on the desktop. I have yet to successfully boot into Ubuntu on this machine except with the live CD.

  • You don't see the menu because Grub is not in the MBR, and nothing apparently points to it. What bootloader do you use to boot Windows? Have you install EasyBCD? – mikewhatever Aug 21 '11 at 3:39

The problem is probably due to the wrong partition being booted when the computer starts.

To fix this boot from a live CD

  • Open system -> administration -> gparted partition editor
  • Check which partition is flagged with boot Partition flagged with boot if the partition flagged with boot is ntfs (File System column) it probably means the computer boots into Windows without passing by grub. (If it is not marked with ntfs do not continue with my instructions)

To fix this right click on your the ext4 (File System column) (the Ubuntu partition) manage flags and select boot.

Restart your PC and you should be presented with the GRUB menu.

If your computer refuses to boot after proceeding with the above steps, reboot from the live CD and mark the lately flagged ntfs partition back with boot.

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  • I am sorry, but IMHO, none of that will help. There is a lot of stuff, so I won't go into too many details, just mention - updating grub from a CD won't update grub on the partition, boot flags are for Windows (grub doesn't care about them). – mikewhatever Aug 21 '11 at 18:03
  • I thought about the problem of sudo update-grub I had read it on a ubuntu forum thread by reading on you are right it doesn't work. Are you sure about your flag stories I had a similar problem (installing grub on a separate partition and changing the flags where enough to solve the problem). Can you think of a way of correcting this post or do you suggest I just delete it? – danjjl Aug 21 '11 at 18:28
  • Check out the Wikipedia article on boot flags. secure.wikimedia.org/wikipedia/en/wiki/Active_partition – mikewhatever Aug 22 '11 at 1:13

You could try pointing the "boot" flag for the drive to the Ubuntu partition. I had to do this for my installation, in order to preserve the ability to use the GRUB Bootloader.

You can use gparted for this. But you will have to do it from a LiveCD in order to prevent the drive from being mounted/used actively.

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