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What should I do when Ubuntu freezes?

I've just tried to install ubuntu 12.04 dual boot OS with Windows 7 and it finished installing in ubuntu. However, it said that the bootloader "grub.." failed to install. The same exact problem here I receive the error 'grub-install /dev/sda failed' while attempting to install Ubuntu as the computer's only OS. . When I tried to restart my computer, it went to the hp screen since my computer is a dv6 hp laptop and then it goes into this black screen with no words or any buttons will work. There is just a blinking underscore that seems like it'll allow me to type but makes error sounds when I type. Is this because I possibly partitioned my memory incorrectly? Any help would be greatly appreciated. I'm very desperate. ANY HELP would be great. Thanks.


I gave up and just reformatted my whole comp. I'm sure there was a better way to do it by either booting it up by the live usb with the ubuntu OS and try to reinstall grub loader.

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marked as duplicate by Marco Ceppi Oct 26 '12 at 19:01

This question was marked as an exact duplicate of an existing question.

Boot off the USB disk or CD-ROM used to install Ubuntu (make sure it's the same version as you have installed).

First, you need to determine what device Ubuntu was installed on. The best way to figure this out is to run Gparted and find the disk that has the ext4 parition. Next to it should be /dev/sdaX (where X is the partition number). Write this down as you'll need it later.

  • Open a terminal (Ctrl+Alt+T)
  • sudo mount /dev/sdaX /mnt
  • sudo grub-setup -d /mnt/boot/grub /dev/sda
  • exit, restart and boot off your HDD

If that doesn't fix your problem, try this:

  • Open a terminal (Ctrl+Alt+T)
  • sudo mount /dev/sdaX /mnt
  • sudo mount --bind /dev /mnt/dev
  • sudo mount -t proc none /mnt/proc
  • sudo mount -t sysfs none /mnt/sys
  • sudo mount -t devpts none /mnt/dev/pts
  • sudo chroot /mnt (You should now see ubuntu@ubuntu:/# as your prompt)
  • sudo grub-setup /dev/sda
  • Exit and boot off your HDD
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Hey Githlar, My problem is that my computer isn't able to even reach the boot screen. Once I turn it in and the hp logo comes on and fades away, the computer goes into a black screen and I can't press any buttons or functions. Does this that I will need a clean install of windows 7? I don't see any other option unless i possibly bring it to a comp fix location. – Chris Oct 12 '12 at 6:50
Did you try booting from the USB stick or CD / DVD? – taneli Oct 12 '12 at 6:55
I tried booting from my usb drive. Sorry for the late response. Didn't see the comment. But the problem is that I'm unable to access anything since I'm brought to a black screen immediately. I can't type anything or access any commands. I'm assuming that the GRUB bootloader for my /dev/sdb <--- (exact one i copied down incase something like this happened) failed to install so my system fails to boot up? – Chris Oct 12 '12 at 7:58
If it's /dev/sdb then it installed the bootloader on your second hard drive. The BIOS tries to boot from the first. The boot sector on your primary hard drive should not have been affected. You need to make sure to change your BIOS settings to boot from the second hard drive. – Chuck R Oct 12 '12 at 22:12
Ok, Right now, I've talked to some buddies of mine and they recommend that I reboot using the windows boot and I'll see what happens from there. I'll come back if that doesn't work. ( I didn't know I could access bios immediately from the screen I was in ) <---Noob :( – Chris Oct 13 '12 at 2:30

I believe I've been plagued with your problem once or twice before. Make sure that your BIOS is set to use the optical or thumb drive first. Its common to forget to set this feature. You should at least be able to access your BIOS screen if you know the key(s) that will launch this utility.

Insert your Ubuntu disk else Windows disk and recover. Note that Windows does not see Ubuntu drives natively at all. If none of this works for you then try another Hard drive but make sure to disconnect the one you cannot boot from. Install. Now install the other drive as a slave and BIOS to make sure your computer boots off the disk you just installed the OS to.

Keep in mind that if you install Ubuntu first, Windows will likely wipe out GRUB-your boot loader. If you get everything working please report back to tell us on how you battled through it for those whom might have similar issues. I wish you luck with your adventure. :P

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