After try: 1. sudo apt-get install python-software-properties && sudo add-apt-repository ppa:freenx-team 2. sudo add-apt-repository ppa:nathan-renniewaldock/ppa && sudo add-apt-repository ppa:freenx-team 3. sudo add-apt-repository ppa:freenx-team None can let the sudo apt-get update to be succeed. Not to mention sudo apt-get install neatx-server. (found no neatx-server) Is there a solution for that? thanks~