I have added a user in Ubuntu 12.04 LTS, but that user is setup only as "standard". I also have a user with full administrative rights (which I presume I will use to make any access rights changes).
How do I change my "standard" user to admin in Ubuntu 12.04 LTS?
Open a terminal with CTRL+ATL+T keys combo and
Bare minimum you need to issue the following command:
sudo usermod -a -G sudo USERNAME
Replace USERNAME with the username of the user you want to promote.
sudo will ask for the password of the already existing administrator.
On my particular system, I am a member of the following groups:
usermod -a -G adm,cdrom,sudo,dip,plugdev,lpadmin,sambashare USERNAME
Mostly a copy paste from a question I bountied on SuperUser here.
If you upvote this answer, please go upvote that one. It deserves it, as it is more correct than the more heavily upvoted and accepted answer.
Login from the user who is already administrator, then click on Dash (Ubuntu icon up left) write user and click on User Accounts
Then unlock by clicking the appropriate button and giving the administrator's password.
Last, click on the user you want to promote and change from Standard to Administrator.
Open a terminal, then add your username to the sudo group with
sudo adduser [yourusername] sudo
From the man page for adduser:
Add an existing user to an existing group
If called with two non-option arguments, adduser will add an existing user to an existing group.
