System worked as sent, but some functions did not work on upgrade. Had to revert to original version. Some functions which appear to be a clearing of cache actually disable the function, and a reboot does not restore the functions. The problem probably is not Linux, but poor programming on the part of Noah. Almost impossible to contact the company except by phone, and then they do not understand anything except Chinese. I probably need to recreate a deleted file, but I cannot communicate with them to find out the name of the file. Recently, the web site pages for nc200 do not load, so I cannot download the operating system to reinstall.