adding user to sudo or admin group in ubuntu

If your system has an admin or sudo group, then we can add the user to that group using the following command.

adduser <username> admin or

adduser <username> sudo.

you should be in sudo or admin login to use the above command

after that if you are not able to get the sudo bash or su -, if you get the below message again

<username> is not in the sudoers file.  This incident will be reported.


Now login to the root user, if you  have permission or boot using Linux resuce CD or boot the PC in recovery mode

1) In root user mode, Type visudo and press enter
this will open /etc/sudoers
add one line...
<username>  ALL = (ALL) ALL