I installed Linux last week, everything fine and I was using the Gnome Desktop. I then selected Preferences/Desktop Switching Tool, rebooted (because dont know how to restart X11)and tried KDE.

I didnt like it much (especially the bouncing ball cursor, and I couldnt find an option to configure my mouse for lefthanded) so I tried to switch back and restart but it having no effect.

Now when i start my PC I have to remember to click on Session and select Gnome before I login otherwise it goes into KDE, Ive tried running the swittching tool half a dozen times without any luck.

create a file in your home dir called

.xinitrc

in this file put the line

exec gnome-session

log out and then back in again

Ok that didnt work but it did help me in a way.
Ive noticed in my home directory .Xclients, .Xclients-defaults & .Xclients-myhostname.

.Xclients-defaults contains gnome
.Xclients-myhostname contains kde
.Xclients calls myhostname

anyway I edited .Xclients-myhostname to use gnome and it now works., seems like a bug in switching tool to me.

I had that problem when I switched from gnome to kde I couldnt switch back but I like kde better anyways