Today, I had the problem that I could no longer remember the
user/password for one of my Xubuntu installations in Virtualbox. So I
downloaded Knoppix 7.0 and had a look what the names of the installed
users were. After that, I had to figure how to reset them. Here is the
HOWTO that I used to reset my user's password (doesn't have to be
"root"). It's scarily easy, to be honest...
"This guide explains how you can reset a forgotten root password with
the help of the Knoppix Linux Live-CD. Afterwards you can log in to
your system as root again."
-- source: http://www.howtoforge.com/how-to-reset-a-forgotten-root-password-with-knopp…
Peter Reutemann, Dept. of Computer Science, University of Waikato, NZ
Ph. +64 (7) 858-5174