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Thanks CrapAtCryptics - I got to the download folder but nothing in there resembles the update. But I do have the name of the file. It`s full title is (as it appears in Control Panel/System and security/Windows Update/View Update History :-
"December, 2016 Security and Quality Roll Up for .NET Framework 3.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, on Windows 7 and Windows Server 2008 R2 for x64 (KB3205402)"
This has downloaded on to my PC every day from 14th December 16 until 11th April 17. From 12th April, the first word changes to April, and the final bracketed number changes to (KB4014981).
Best of luck!