I am attempting my first source tarball install, which uses the su command and require me to enter the password. Unfortunately the system keeps rejecting my password and I cannot get into the super user status at all. What can I do?

I have been using Ubuntu (now 9.04) on a single notebook PC for more than 6 months now. Is there another password for the super user, I cant remember the installation process since it happened some time back.

Any suggestions would be greatly appreciated. I hope I don't have to re-install Ubuntu.

Thank you.

Ubuntu disables the root account by default.

To activate it:
sudo passwd root
it will ask for you regular user name, and then for a new root password.

Even after doing this, many operations will still want your **user** password, so it can get confusing.

That was a great relief. Thank you very much.