Kde4 will not launch either firefox or konqueror. Firefox bounces its logo for a while, which then disappears. Konqueror puts up an error message saying that libjpeg could not be found, and KHTML therefore failed.
It is an updated install, and your suggestion was just what was needed. I think my 70-year-old English English tended to read 'UPDATING' as to do with preparations for the future rather than reconfiguring the past to work in the present, but now the browsers work well, and I am looking at other packages. Many thanks.