when I get to my file and want to change the group or owner. I get the drop down menu and make my selection and click on it but I keep getting a error message that states I don't have permission to change this file.

All I want to do is change the group on one of my files but it will not let me do it.

If you have any help I could use it.

I forgot to tell you I am using Ubuntu 6.10

Terminal / Console is the way to go:
sudo chown user:group /path/to/the/file

tedegar when I use that command I keep getting a invalid user messages. I must be doing something wrong. Could you help me on this.

Also when I use this command sudo chgrp (user name) (file name) I get a operation not permitted. I don't know why it will not let me change the group name. The owner of the filer is root. The file I want to change is a open office file My_Story.odt. It has an group name of plugdev as dose all the other files in that drive.

You should be running as the user who installed ubuntu, if not, you may not have permissions to sudo.
Try the following in a terminal window:
groups
This should list the groups your username is in.
For me, it looks like this:
tredegar adm dialout cdrom floppy audio dip video plugdev lpadmin scanner admin
Then try
sudo -i
It should ask for your password and then let you become root.
Then you can (now you are root) try the command chgrp groupname /path/to/the/file

You'll have to change "groupname" to the name of a group that already exists.
Type exit at the terminal to cease being root, before you do something by mistake.

This really doesn't help me understand what is happening at all.
In future, please copy & paste the commands you gave, and the exact error message(s).

OK I used the commands that you suggested and this is what I got.

ronbrooks@prodigy:~$ sudo -i
root@prodigy:~# chgrp ronbrooks /media/hdb6/My_Story.odt
chgrp: changing group of `/media/hdb6/My_Story.odt': Operation not permitted

If you have any other suggestion please let me know.

I can still use the drive because I am a member of the group plugdev but I would like to change it to my own group. The drive is owned by root and all groups on that drive are plugdev but it will not let me change. I don't know but do I need to unmount the drive before the change are made.

Thank you: You can become root, but the chgrp is not permitted.
This is strange.
I'd like to see the output of ls -al /media and cat /etc/fstab | grep hdb6 please.
Do you have write privileges for /dev/hdb6 ? It's not an NTFS partition by any chance is it?

I expect udev rules has assigned your drive to be a member of the group plugdev, and set its permissions. Maybe, if you want this to be different, you should be looking at your /etc/udev/rules.d/ rules files, and making the changes there.
I'm at work now, on MS, so dont have the link I want, but you can google for "Writing udev rules".

Unmounting the drive will not help.

I was able to do it by changing my fstab file so now I am the owner and user is the group. I am able now to make any changes I need to because I am the owner.

Thanks for your help.