Snautzer, my explanation of how my PC was set up was not very clear, I appreciate. I'm sure I've used the wrong terminology, as I'm certainly not a computer guru !
However, the person who has supplied this PC and Win 10, and all my previous PCs and related stuff over the past 15 years or so, is not an amateur - he has been in 'the business' for around 40 years, and for the past 20 years or so, has run his own company, designing and marketing software, as well as supplying hardware and security and back-up services to commercial and industrial clients.
He explained what he had done as he was sitting in front of my PC with me, and, at the time, it all made sense when explained in simple terms. But, as there was so much for me to absorb, especially as he investigated and found the source of my 'problem' with me watching, I'm afraid my 'translation' of this has suffered !
Needless to say that everything has been checked, and everything is current, and operating how it should be.
Given that the supply of equipment, Win 10 etc was done at 'mate's rates', and the transfer of all my programmes, data, files, folders etc was included in the very reasonable final price, as is the support, and also security back-up, all undertaken in his spare time, during and out of working hours, I can fully understand if he took the shortest path.
As I understood it when explained, if he was to do a 'clean' installation, transferring my stuff would not be a problem, but he didn't want to lose any of the programmes I had installed, and It is this that, for whatever reason, has resulted in the use of part of the available "processing power".
Now that he knows which programmes I wish to retain and which can be deleted, he can now easily record these, do a 'clean' WIN 10 up-date installation, and then re-install those programmes I want to retain which, apparently, will 'free up' some space and allow the full potential of the PC processor.
Again, not the best description / explanation (computer stuff, to me, is like a woman's brain !), but it all made sense to me at the time!