Further update chaps...
...as I type this my mate is fetching back the laptop fully "S".
When he switched it on, it fired up as normal. Carefully shut it down and then restarted it, still ok. Investigating he found an incident with Avast that caused the validation problems mentioned above by Tarq57. Cleared that up and found 498 important updates that madame had ignored!! That has been sorted.
Now that it has been properly "fettled" it is, in the words of the old wireless operators, "singing like a box of birds."
He had the tools to get past the blank wall that I faced (I believe it involved LINUX). All is well and a modest cost paid. Happiness reigns in the Rossian household again. Hurrah!!
The Ancient Mariner