Well, I tried... I really tried to get on with Windows 10 but with data transfer speeds of a few KB/sec over a gigabit network, I decided enough was enough and chose to avail myself of Microsoft's kind and thoughtful willingness to allow roll-back to Windows 7.
I particularly liked the bit where, after completely messing up my PC beyond recovery they kindly present me with a terminal BSoD.
Oddly enough, I'm by no means the first to benefit from the bounteous Micro$oft in just this very manner, according to the 'net.
Thank god I'm paranoid about backup of data. Luckily, I lost nothing, even though Micro$oft saw fit to trash my C Drive without any warning.
So, after a pleasant hour or two of re-installation I now have a Windows 7 desktop in front of me and that's the way it's going to stay.
BTW. Network data transfer? Blazingly fast