can't login to root fedora 10
 

I am a newbie. I have installed Fedora 10 and set a root password.
When I try and login as root from desktop it says can't authenticate. I no I am using the correct password.
Any thoughts on this?

How are you authenticating? su, sudo, gksu?

from desktop
 

I have either username which logs in fine.
Then I have other where I am typing in root and trying to use my root password, but it says unable to authenticate.
If I go into root via the console using su it works fine.

I don't understand the last part of the answer. Can you use kdesu or sudo after logging in as a regular user. You shouldn't log in to a desktop environment as root.

Is this with X running, or from a virtual terminal? Can you log in as root on one of the virtual terminals?

Is this part after trying kdesu or gksu?

If you can su to root in the console, look at your logs. The information there may have more information.

will gnome/kde allow you to log in as root from the GUI? or console as default?

I know you can turn root login off from the console and so can only SU to root after authenticating as a user first.

I would have to look to be certain about Fedora 10. Ubuntu totally locks out root logins. I think that the PAM configuration for KDM/GDM might disallow root logins. Please don't change this. It is vary dangerous running the entire desktop as root. This is one of the things that makes many Windows systems so dangerous, before Vista. Please don't repeat their mistake.

You can use "su -" in the terminal and enter a series of commands as root. You can use "kdesu" or the gnome equivalent to launch a graphical editor or system config wizard as root. You can use "sudo" to run a single command as root, and have that command logged, which could save your butt in the future if you made a reversible change and can't remember the exact command. You can launch a configuration wizard from the menu. You will be prompted for the root password. Here I've given 4 options. You don't and shouldn't log into KDE or Gnome as the admin. I've only done it a couple times (I don't remember the circumstances why I did) and felt sick and guilty for a week afterwards!

in fedora 10 YOU CAN NO LONGER LOGIN AS ROOT USING THE GUI
unless you hack the operating system , this is NOT RECOMMENDED and can cause fedora 10 to crash .
You can login using su, su - once you are logged in as a normal user .
-- the not recommended hack instructions -- you might experience ODD behavior from fedora if you do this ---
http://forums.fedoraforum.org/showthread.php?t=209638