jl_harry12 ,

I am really surprised that you still report a problem of doing "fdisk -l".

In Post #55 there are two boxes showing two different methods of getting root privilege in Ubuntu

The first one I demonstrated with
Code:
ubuntu@ubuntu:~$ sudo su
root@ubuntu:/home/ubuntu# fdisk -l
You can see the prompt changed immediately to the root user here.

In the second I did
Code:
ubuntu@ubuntu:~$ sudo fdisk -l
They all work perfectly as the Post shows.

Is my explanation in Post #51 not sufficient?

I am not suspecting your drive going bad but just to show "fdisk-l" could only fail if the disk is not readable. Your problem here is Ubuntu needs to see the root privilege up front before releasing the content of "fdisk -l" to you, so supply the red bits.