Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have installed (not live CD) Ubuntu on a USB stick, and now having dual boot with Windows. How can I use this USB on another machine, as the latter does not have grub.

How to make the USB standalone bootable without grub, working on any machine?

share|improve this question
Just boot to the USB stick from BIOS. I assume GRUB is installed on there when you installed Ubuntu. – hexafraction Sep 16 '12 at 19:42
@ObsessiveFOSS I tried this, but apparently GRUB has been only installed on the hard drive of machine A. When booting from USB on machine B, it will not startup. – All Sep 16 '12 at 19:45
up vote 2 down vote accepted

You need to have grub installed on the USB stick or the hard disk of the host machine. In your case as you want it bootable on any machine, you need it installed on the USB stick and boot the USB using BIOS option.

OBS: there is no problem on your machine to have GRUB on your HD (to dual boot with windows) and on the stick. If you boot from your HD, you'll have your usual options and GRUB on the stick will not be used. when you boot from the USB, GRUB on the stick will be used and you will have the options you defined there (probably only booting the Ubuntu on the stick as if you use it on many machines, you don't know what will be on these machines)

Installing GRUB2 on the USB stick:

Open a terminal and type:

sudo su
fdisk -l #to see the device for your USB stick
# Replace all /dev/sdx with your USB device from line above
mkdir /mnt/USB && mount /dev/sdx /mnt/USB #DON'T FORGET TO REPLACE
grub-install --force --no-floppy --root-directory=/mnt/USB /dev/sdx #REPLACE
share|improve this answer
I thought of that, but doesn't it affect booting on the first machine? as GRUB exists on both the hard drive and USB? – All Sep 16 '12 at 21:45
I thought you were worried about that and was completing answer. Please see the update – laurent Sep 16 '12 at 21:46
Can you explain how to install GRUB for the OP? – hexafraction Sep 16 '12 at 23:21
@ObsessiveFOSS - sure, I will update the answer to include that – laurent Sep 17 '12 at 13:05

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.