Ubuntu 7.10 doesn't authenticate with sudo -i and not getting GUI
After installing Ubuntu 7.10 (Server edition), I tried getting GUI by downloading packages with wget command,but nothing worked.Also,after few logins,when i again started my comp,after running sudo -i,i got error saying
<comp name> is not in sudoers file.This incident will be reported.
$sendmail:fatal: open /etc/postfix/main.cf : No such file or directory
I can't login as root and cant make any changes.Pls help.