Am Freitag, 14. Dezember 2012, 16:10:07 schrieb Uwe Brauer:
> > 1st: can you log in as root or switch to root account using 'su -' ?
> 
> no!

that is bad.
always set a password for root before messing around :)
(sudo passwd root)

> > 2nd: you can always install a new sudoers file from a live CD as long as
> > your file system is not encrypted..
> 
> it is not encrypted, but suppose I use a say Kubuntu 10.04 live CD, how 
> do install the new sudoers file?

well, you can download a sample file from the internet or, if you still have a 
default sudoers file, edit that from the live cd.
mount your HD first, of course.

werner