Question Author
Thanks again Buenchico!
I carried out your instructions to the letter - and saw an instant improvement - once I had deleted the obviously high figures. However, I have not solved all the problems, because today I can't get on to the internet on my 'best' laptop in Firefox, Internet Explorer or Avast. I was able to watch rugby on my old laptop today, in Firefox, without any 'freezes' - a hitherto unknown experience!
As ever, thank you very much for everything. With the best will in the world, I hope I don't have to bother you again for a while!
Best regards
Chick