Thank you for that pointer to the other thread!  It certainly contains much food for thought!
I don't have a Dell machine, but I assume this is not a crucial factor in the equation?
It does seem to offer some hope [I had all but given up?] and
I shall attempt to digest the information and let you know how I get on.
Once again... many thanks for all your help.  I have not had any help at all from any other source and I am extremely grateful for your kind consideration.  Yours is the only forum that has replied to my cry for help.