Apologies that I keep posting messages (in despair!)
Should I now go through all your uninstallation instructions again and try re-installing from the download link that you just sent me?
My concern is that there must be more to it all as whenever I try to re-install, the application just does not show up in Apps and Features (in Settings), nor from the applications listed in Start.
Now it doesn't even offer any choices of monochrome - greyscale - colour!
What now, please?
Thank you for your continued patience. Please would you read through the message posted at the same time as yours came through today, in which I detail all the problems?