Thanks All for your advice re my PC.
As has been suggested it might be just age and Windows updates over the years. There seems to be plenty of space on C drive if that is relevant. I have decided, wisely I hope, to leave it well alone on the premise that
'if it ain't broke don't try and fix it'!. While it continues to work 'reasonably' I will put up with it.
I am OK if I can see the big ends going round but these innate things that just sit there where one doesn't know if it is working or not are beyond me.
I will therefor quit whilst I am not too far behind .............
Thanks again.
Geoff