You are too vague.

First, I think that .xinitrc only runs if you start X by the ``startx''
command.  .xsession only runs if you are using XDM.  Which do you do?
(You shouldn't need to worry about both files.)

You say that you don't know the name of the ``default gui'' that does run.
But saying that ``the'' or ``a'' GUI is running really doesn't say
anything.  Applications have GUI's---for example, GNU EMACS has a GUI, if
you run it under X.  KDE (and X, and window managers such as twm, ...) are
not GUI's, really.  So let's get the terminology a little straighter:

 You *need* to run X in order to run KDE.  KDE does *not* provide a
 graphics system.  (That's what X is for.)  So, you should still be
 running X.  That's not a problem.

 You *almost*need* a window manager, such as twm.  twm ships with
 the system, but I don't think that it's quite fair to call it the
 default.  You have to have a line in your .xinitrc or .xsession
 specifically asking for twm to run, if you want twm.

 KDE is not a window manager.  It does *include* its own window
 manager (which it would prefer that you run).  If you're using KDE,
 you probably should not be running a seperate window manager.  (KDE
 is very integrated; at least visually, a seperate window manager
 probably won't look so good.  There may be functional problems, as
 well.)

 Instead, KDE is a ``desktop'', and is comparable to GNOME, but is
 not comparable to twm (or blackbox, or WindowMaker, or...).

So, you *should* have X running.  If that's what you mean by ``the default
GUI'', then there's no problem.

Before attempting to guess further about your situation, perhaps you can
simply *say* what your .xinitrc looks like (or, if you're using XDM, what
your .xsession looks like).  The file should be short, in either case, so
you should be able to simply post the file in its entirety.


  ``I probably don't know what I'm talking about.'' --rauch@math.rice.edu