I strictly followed the steps of website:http://wiki.ros.org/indigo/Installation/Ubuntu and I had problem when I tried to set up my key. Then I changed the command to sudo -E apt-key adv --keyserver hkp://pool.sks-keyservers.net --recv-key 0xB01FA116. It worked and showed me that manage apt's list of trusted keys and something. But then when I tried to install package and I got the problem of unable to locate package ros-indigo-desktop-full. I checked and found some people had this problem since his ubuntu version was wrong but my ubuntu is 14.04. What can I do? I will really appreciate it if someone can help me.