How to determine what to delete in a partition to install Ubuntu,

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On Mon, 2015-10-05 at 15:13 -0400, Richard Barmann wrote:
> If so, am I right that it says "Thunar"?
> > Yes it is, But the desktop I am refering to is when you first boot
> > up Xfce the screen shows some files and pictures before I go to the
> > Desktop.

You turn on your computer, then you boot your Xfce Ubuntu. When the boot
process finished, there is a screen were you need to type your user
password to login. Do you mean that screen?

If so, post the output of

  ps aux | grep dm

if not, then try to explain more precisely what screen/"desktop" you are
talking about.

We already know this about your set-up:
  Graphics    : 1. An unknown on-board graphics
                2. Nvidia GeForce 6200
  Printer     : HP Officejet 4630
  Monitor     : Emprex LM2201
  DE          : Xfce
  Ubuntu      : 15.04
  Architecture: i686
  Linux       : 3.19.0-25-generic
  $ wmctrl -m
  Name: Xfwm4
  Class: xfwm4
  PID: 1422
  Window manager's "showing the desktop" mode: N/A

It doesn't harm to know the output of
  cat /etc/X11/xorg.conf
assumed we continue troubleshooting.

Regards,
Ralf

PS: I hope somebody else will chime in again ;).