I have read about changing permissions until I'm cross-eyed, and maybe my 12 medications don't help either! Could someone give me a specific entry for changing a file and then I'll work my way from there?

The file is "etc" in FILE SYSTEM with a location of /, volume /. (I have recently added Kubuntu to my Ubuntu Dapper and the DEFAULT DISPLAY MANAGER file is in the "X11" file within the "etc" file.)

When I open the "etc" file and click on permissions, it says I don't have ownership.

Could you give me the exact command to change the root permission for this file please? I'm still pretty new, 100% Linux now, but do have some issues grasping things until they click..thanks.

well back up and explain what you actually want to acheive... what's the end goal here? your user in ubuntu is not root, and shouldn't be, as such you are not meant to "own" /etc (a directory, not a file btw...) if you did, things would probably break a lot...

You shouldn't probably be changing the permissions of /etc directory (which is a file, that's correct, but a special kind of file) nor anything under it. If you need to change something, use either root account (in Ubuntu you'll need to first unlock it) or simply sudo which is better in cases like this. For example you can run this command to edit some file that you don't have permissions for, if you have sudo configured (and you do, if you're using the first user account created during Ubuntu setup):
..then it asks for your (own) password and once you type it in, the file is opened with 'gedit'. Works for clear-text files. If you're not interested in graphical editors, use 'sudo' instead of 'gksudo' (the latter one is graphical dialog) and a command-line text editor.

change the ownership using chown command

If you chown /etc you WILL break sh*t ... I'm with acid_kewpie on this one.

Thank you all for your input, bouncer gave me a command and that is what I needed.

Here is what I was trying to do, based on KUBUNTU instructions:

"To change default from KDE to GNOME you need to change this file:

/etc/X11/default-display-manager

The default can always be changed later by modifying the:

/etc/X11/default-display-manager file

For KDM, the file should read /usr/bin/kdm;

for GDM, the file should read /usr/sbin/gdm"

So, When I want to change this default from KDE to GNOME, I had to get permission to do this, which prompted my question. Secondly, I was previously successful in changing this from GDM TO KDM, SO I did something right, but when trying to change it back I draw a blank.

Also, now that I have KDE, I'm not sure I like the overall features compared to Ubuntu so would like to uninstall it, but when use Synaptic Manager and uninstall all KDE items, I still am getting the KDE log-in screen after my initial brown Ubuntu screen appears and the system loads. Thx agin