How to add the Universe & Multiverse repositories graphically

Here’s how to add the universe and multiverse repositories.

Open Software Sources. System > Administration > Software Sources
Check the boxes for Community-maintained Open Source software (universe) & Software restricted by copyright or legal issues (multiverse)
Click Close. Another box should pop up asking if you want to reload, click Reload.
If you clicked Close, and a window didn’t [...]

How to add the Universe & Multiverse repositories from the command line

Enabling the Universe & Multiverse repositories will give you access to tons of software that your Ubuntu system doesn’t give you access to by default. Here is how to enable them.

Open a Terminal. Applications > Accessories > Terminal
Type in:

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

This makes a copy of the file we’re going to modify, in case [...]