I have SuSE 7.0 installed on my desktop along with RH 7.3. The function you are looking for is not in Red Hat.
RH has an executable called "switchdesk" but as far as I can tell all it does is rebuild a file called /home/<username>/.Xclient-default. Then, this file only gets used if you get out of X and go back in with startx.
If you normally login thru the gui screen (i.e., you don't use startx), then you really don't benefit from switchdesk. (Someone correct me if I'm wrong!!)
Perhaps later I'll mount my SuSE partition in RH and try to change the desktop with the SuSE command (what's the worse that can happen? :-> )
>----- Original Message -----
>From: "Christian Schlettig" <schlettig evaco de>
>To: "redhat-install" <redhat-install-list redhat com>
>Sent: Wednesday, September 11, 2002 1:54 PM
>>is it possible to switch the desktop direct from >gnome to kde and vice
>>versa without logging out and in?
>>I remember that a old suse i had could manage this.