Open a terminal and type this
sudo apt-key --keyserver keyserver.ubuntu.com --recv-keys DFE4915
and then this
software-properties-gtk
then enter, go to the Other Software tab and click on Add..
If you already see the aitekweb.com line like in the picture then skip adding the APT line
the complete APT line for AitalMAC package repository is
deb http://aitekweb.com/my-repository-x64 trusty main
After adding the repository you will be asked again for password, and again password is
123
Then close software & updates, and in the terminal type
sudo apt update
Now all of AitalMAC packages for Ubuntu 14.04 x64 are available