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my dvd-rw was not working. but i had to install linux. so i installed ubuntu from the iso using demons tool. But when i am opening the terminal to create an user,it's prompting that only root have the permission to create an user.

i am trying to use "su" command but it's showing that authentication failed.

How can i become the root?

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Please use question titles which describe the question. it's a about ubuntu doesn't help us help you. Also try to use complete sentences and capitalization. – AndrejaKo Jul 7 '10 at 9:22
They disabled root on your machine because they knew you'd misuse it. – msw Jul 7 '10 at 9:51

sudo -i then type your pass and you will root

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sudo bash

instead. You may also wish to install a graphical environment, such as KDE or GNOME; they offer their own ways to issue commands as root.

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To become root type:

sudo su -

It is however more secure and "better" to do everything using the sudo command to elevate privileges on a per command basis rather than logging in as root.

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sudo -i does the same thing in one command – matthias krull Jul 7 '10 at 11:14

If you are like me and really want to use su and understand why it is disabled, one of the ways to do it would be:

sudo passwd root

or just

sudo passwd

This will allow you to create password for root and you will be able to use that user normally.

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Ig the OP understood why it is disabled, he wouldn't need to ask the question. – msw Jul 7 '10 at 9:48

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