Unable to locate package chntpw

Question

To overwrite a Windows 7 password, one can boot from a Ubuntu LiveCD and run chntpw.

Unfortunately, installing chntpw is not so easy:

$ sudo apt-get install chntpw
E: Unable to locate package chntpw

Answer 1

First open the Ubuntu Software Center, in the Edit menu click Software Sources..., and in the window that appears enable universe as seen below:

Then run sudo apt-get update.

You should now be able to install chntpw using sudo apt-get install chntpw.

Answer 2

Do this from the terminal

sudo add-apt-repository universe
sudo apt-get update
sudo apt-get install chntpw