View Full Version : The dual boot doesn't works. I can't have Ubuntu and Windows

April 15th, 2013, 11:59 PM

I have Windows 7 installed.

I install Ubuntu, so, I have the GRUB, but just works if I choose Ubuntu.

If I choose Windows 7 appears the message "BOOTMGR is missing".

If I fix the Windows 7 boot using the Windows CD, the GRUB disappear (of course).

If I fix the GRUB using the Ubuntu Live CD, the GRUB get back, but if I choose Windows... "BOOTMGR is missing".

What the way?


April 16th, 2013, 12:30 AM
Did you install grub to the Windows NTFS PBR - partition boot sector. Windows in the MBR tries to boot the Windows PBR which must have Windows boot code even for NTFS data partitions.

Best to see details.
Post the link to the BootInfo report that this creates. Is part of Boot-Repair:
Boot Repair -Also handles LVM, GPT, separate /boot and UEFI dual boot.:
You can repair many boot issues with this or 'Create BootInfo' report (Other Options) & post the link it creates, so we can see your exact configuration and diagnose advanced problems.
Install in Ubuntu liveCD or USB or Full RepairCD with Boot-Repair (for newer computers)

April 16th, 2013, 01:18 AM

I installed the GRUB on my Linux partition.

I followed those instructions:

$ sudo fdisk -l

$ sudo mount -t ext4 /dev/sda6 /mnt

$ sudo grub-install --root-directory=/mnt /dev/sda

"sda6" is my Linux partition.

Ok, I will use Boot-Info to show the boot parameters here.


April 16th, 2013, 02:13 AM

Here I am, after run Boot-Info.

The URL >> http://paste.ubuntu.com/5711929/

Ok, I`m seeing that my Linux partition is the sda7.

I`m not crazy, it was sda6 a couple of days ago.

I used sudo fdisk -l in the terminal and confirmed sda7 as the Linux partition.

How can I fix my boot (get back my dual boot)?

Does sudo grub-install --root-directory=/mnt /dev/sda work?


April 16th, 2013, 03:23 AM
May I ask what command did you use when you install GRUB using the live environment?

Hmmm...If I were to do this dual boot, as I always do, I would install GRUB in the /dev/sda partition itself. That would remove the windows bootloader and let GRUB takeover everything on boot.

You could try and if it doesn't work, use the Win7 DVD again to repair boot and proceed with other solutions.

April 16th, 2013, 04:45 AM
Boot-Repair will reinstall grub automatically. Or you can do it manually:

#Comments are anything after the #, enter commands in terminal session
#Install MBR from liveCD/DVD/USB, Ubuntu install on sda7 and want grub2's bootloader in drive sda's MBR:
#Find linux partition, change sda7 if not correct:
sudo fdisk -l
#confirm that linux is sda7
sudo mount /dev/sda7 /mnt
sudo grub-install --root-directory=/mnt/ /dev/sda
# The above command should work but they now suggest this command for grub 1.99 with Natty 11.04 or later - uses boot not root.:
sudo grub-install --boot-directory=/mnt/boot /dev/sda
#If that returns any errors run:
sudo grub-install --recheck --root-directory=/mnt/ /dev/sda

# If no errors on previous commands reboot into working system and run this:
sudo update-grub

How to restore the Ubuntu/XP/Vista/7 bootloader
Reinstall grub2 - Short version & full chroot version
https://help.ubuntu.com/community/Grub2#Reinstalling GRUB2
Grub2 info & full chroot version - also METHOD 3 - CHROOT:

April 24th, 2013, 08:58 PM
oldfred, thanks!

Sorry for my late. I did today the procedure.


Boot-Repair saved me! It's solved!

I loved this program.


oldfred, thanks again!

nerdtron, thanks!