Ubuntu: Some user not in sudoers file

Bumped into this on my Ubuntu where I could no longer be super user on my machine so I can install stuff and get the latest updates.

After googling the error message, I discovered a solution that worked.

Not exactly sure how this has happened but I am sure it was a minor mistake on some update.

Symptoms
Can no longer become SUPER USER to do amazing stuff like, being able to install software.
Cannot update software
Cannot create new users.
Cannot do much other than regular user stuff.
Admin menu appears samaller
Add Remove Menu item is gone.

Known Errors
When you type "sudo bash" and type in the word, you recieve an error like
This user is "not in sudoers file".
Sudoers file is located in /etc/sudoers

Resolution
You need to know a small bit of "vi" or "vim" to edit the sudoers file. "vim" is slightly easier. There should be a cheat sheet online( Google search "vi cheat sheet"). Really you only need to know how to

• "Insert a line"
• "delete a line"
  
• "Save and Quit" and
• "Quit without Saving"

You can only edit /etc/sudoers file visudo.

1. In the boot up menu, select "recovery" mode for the latest kernel (You may need to press "esc" key).
2. You will come to a choice menu, select "shell prompt"
3. Run the command "visudo" and insert a line similar to this

someuser    ALL=(ALL) ALL

Around here.

# User privilege specification
root    ALL=(ALL) ALL
someuser    ALL=(ALL) ALL

4. Save the file and then reboot the machine safely by typing at prompt

shutdown -r 0

5. Once machine has rebooted, login again type in a new terminal the following

sudo addgroup someuser admin

You should now be able to do SUPER user stuff again.