Hi Koli, long time no see!
Follow Oldbeefer's advice, and be persistent (very persistent). Did he mention persistence?
Try to keep an accurate log, including screenshots of errors, ping results and such like - if your mate can do the same then it is more evidence / ammunition (delete as appropriate!).
You can make a batch file with something like:
to help make recording date and time with results - and of course you can pipe it to a file.
SD