@Andrew-H I can connect now ok with ethernet to the powerline adaptors, and I see all 5 of them. Thanks - but some of my comments stand (version, date, contextual help within the program).

@Andrew-H I have a partial answer to my own problem. If your windows PC is connected wirelessly, TPplc utility does not work correctly. If you connect by ethernet, you can enroll the adaptors. But...

There are real problems with the TPplc utility. I followed some other threads on here and I downloaded onto my Windows 10 PC what I think is the latest version of TPplc utility (although the software...