I've just uploaded some photos that explain how to use Irfanview to desaturate images with a bit more control and subtlety than hitting the "desaturate" button.
Harry's Filters can be downloaded from the Irfanview site and are easy to use, once one gets the hang of how to access them. There is a cheerful "play" function, where the system moves of its own accord and if you see an effect you like you just hit the "stop" button.
It's worth noting that freeware programs are very good for amateur use and do not fill hard drives with vast amounts of filters that may or may not be of use.
The photos in question may be viewed by hitting the title bar.
Spring has hit Dublin and computing is way down the list of activities from now on.
Many thanks to all who continue to visit and post friendly comments here.