I am new to Ubuntu. I have installed Ubuntu 12.10 on a fujitsu amilo 1536 notebook, and it works just fine.
To extract a tar archive I need root privileges but I can't get them. I can't use
sudo because the user I use is not in the sudoers file (although it's an administrator account) and i also can't edit the sudo list manually, because of insufficient privileges. root password is unknown to me as usual for Ubuntu.
Any idea how to handle this?