root password not given to sys but requires one to enter root. What is password?

First let me thank you in advance for your help to a newbie.

I installed Ubuntu from a disk that came with Linux Format magazine #155 (March 2012) .

It is version 11.10 with Gnome.

The installation went well with no errors or problems.

During the set-up it asked for a user name, computer name and user password. I supplied all three.

Later as I was working in the command-line I attempted to gain access as root.

When I was asked to enter my password I assumed it was what I entered earlier, but I was wrong.

It did not accept the password.

I cannot access root and have no idea how to unlock the root user. Any suggestions?

Thank you,
Keith
(new kid on the block)