Changing desktop doesn't work !!!

["Javier Fradiletti" <jefa adinet com uy>]

Since i change the desktop from Gnome to FCWS (or something like that) with
the Desktop Switching Tool of Gnome, i've never could change it back again.

Here is my question: can root user (or maybe the current user itself) change
that in some configuration file somewhere in the filesystem ????

Regards,

javier f.