Ta for the pointer to
how to recover missing control panel icons ? - Microsoft Community
I followed the suggestion all of the way to the second paragraph where it says " Right Click on it and rename it using cpZ as the extension" whereupon I failed miserably as I don't have permissions to mess with the files in Win32 directory. Aaaarrrrgh. I have had the machine from new but doubt that I ever knew the super user password.
A number of the .cpl files fail to work when clicked, namely all of those connected to the nVidia display driver and also the update manager.
The add or remove programme does function though so I have used it to remove the Java, which is where I started this from.
Rans6........