I have a working tablet. As already documented above the KB4056892 was at fault, however getting rid of it and staying rid of it was another matter.
Using windows 10 home on my tablet (no point in pro) you need to take some extra steps to keep things sane:
Go to settings | Network & Internet | Change Connection Properties | Set as metered connection : Turn this ON
(this stops windows from downloading updates).
The tablet now works - I cannot do this on another PC I am using as I really do need updates.
Now because metered connections mean no updates downloaded make sure you get an anti-virus separate from windows defender as I suspect windows will not be downloading updates for defender.
Fingers crossed this keeps it at bay....