Changed from KDE to Gnome...on it's own!
For some reason or other when I rebooted my computer, my GUI changed from KDE to Gnome. The only hint is I uninstalled Kmix just prior.
The reason I got rid of Kmix was because I had installed ALSA because of problems I'm having with my audio and I thought it would be a good idea to delete in case of any clash. Was that not sensible?
I have re-introduced Kmix.
Anyway how do I bring KDE back and is it possible to swap between the two GUI's at random?