I successfully installed OpenCPN first time on my test PC, but I am now trying and failing to do so on the PC I want to use on the boat. This is a Gigabyte Brix with no internal hard drive and the OS programs and files all on an external USB3 drive. That should make no difference to installation as the original test was on the same PC with the drive fitted internally. I have run the "sudo apt install software-properties-common" command, rebooted then run "sudo add-apt-repository ppa:opencpn/opencpn" and "sudo apt-get update" commands, but OpenCPN has not loaded. I think I have missed out getting a particular package, but although I can find such packages listed from the OpenCPN website I can find no means of installing them. What puzzles me is that first time around it all installed and worked. I even got the GPS to show a fix.