Estaba leyendo Ubuntu Life y sus pruebas con KDE 4.1 (que gracias a él también pude probar) y se me ha ocurrido que podía publicar estos comandos que tengo guardados para dejar una instalación “limpia”.

Asi que si has instalado Ubuntu y quieres probar Kubuntu o Xubuntu puedes instalarlos así: sudo aptitude install kubuntu-desktop sudo aptitude install xubuntu-desktop

Luego en la ventana de entrada puedes elegir entre uno y otro, hasta aquí todo bien. Pero que pasa si ahora quieres quedarte con KDE (kubuntu) y eliminar cualquier rastro de GNOME o XFCE.
Y a quien no le ha pasado que tras instalar otro escritorio quedan restos por todas partes del anterior? Aquí la solución.

Si instalaste GNOME con apt-get/synaptic en lugar de con aptitude o ya te venía al instalar ubuntu puedes desinstalarlo con este supercomando:

Borrar Ubuntu (GNOME) (instalando KDE)

sudo apt-get remove alacarte app-install-data-commercial apport-gtk apturl at-spi bluez-gnome brasero brltty-x11 bug-buddy capplets-data cli-common compiz compiz-core compiz-fusion-plugins-extra compiz-fusion-plugins-main compiz-gnome compiz-plugins compizconfig-backend-gconf contact-lookup-applet dbus-x11 dcraw deskbar-applet desktop-file-utils displayconfig-gtk diveintopython doc-base docbook-xml ekiga eog espeak espeak-data evince evolution evolution-common evolution-data-server evolution-data-server-common evolution-exchange evolution-plugins evolution-webcal example-content f-spot fast-user-switch-applet file-roller firefox firefox-3.0 firefox-3.0-gnome-support firefox-gnome-support gamin gcalctool gconf-editor gconf2 gconf2-common gdebi gdm gedit gedit-common gimp gimp-data gimp-gnomevfs gimp-python gksu gnome-about gnome-accessibility-themes gnome-app-install gnome-applets gnome-applets-data gnome-cards-data gnome-control-center gnome-desktop-data gnome-doc-utils gnome-games gnome-games-data gnome-icon-theme gnome-keyring gnome-mag gnome-media gnome-media-common gnome-menus gnome-mime-data gnome-mount gnome-netstatus-applet gnome-nettool gnome-orca gnome-panel gnome-panel-data gnome-pilot gnome-pilot-conduits gnome-power-manager gnome-screensaver gnome-session gnome-settings-daemon gnome-spell gnome-system-monitor gnome-system-tools gnome-terminal gnome-terminal-data gnome-themes gnome-user-guide gnome-utils gnome-volume-manager gstreamer0.10-alsa gstreamer0.10-gnomevfs gstreamer0.10-plugins-base gstreamer0.10-plugins-base-apps gstreamer0.10-plugins-good gstreamer0.10-pulseaudio gstreamer0.10-tools gstreamer0.10-x gtk2-engines gtk2-engines-murrine gtk2-engines-pixbuf gtk2-engines-ubuntulooks gtkhtml3.14 gucharmap guile-1.6-libs gvfs gvfs-backends gvfs-fuse human-icon-theme human-theme hwtest hwtest-gtk im-switch jockey-gtk language-selector libalut0 libarchive1 libart2.0-cil libatspi1.0-0 libavahi-glib1 libavahi-ui0 libavc1394-0 libbeagle1 libbonobo2-0 libbonobo2-common libbonoboui2-0 libbonoboui2-common libcairo-perl libcairomm-1.0-1 libcamel1.2-11 libcdio-cdda0 libcdio-paranoia0 libcdio7 libcompizconfig0 libdecoration0 libdeskbar-tracker libdmx1 libdv4 libebook1.2-9 libecal1.2-7 libedata-book1.2-2 libedata-cal1.2-6 libedataserver1.2-9 libedataserverui1.2-8 libeel2-2 libeel2-data libegroupwise1.2-13 libenchant1c2a libespeak1 libexchange-storage1.2-3 libexempi3 libflickrnet2.1.5-cil libgail-common libgail-gnome-module libgail18 libgamin0 libgconf2-4 libgconf2.0-cil libgdata-google1.2-1 libgdata1.2-1 libggz2 libggzcore9 libggzmod4 libgimp2.0 libgksu2-0 libglade2-0 libglade2.0-cil libglew1.5 libglib-perl libglib2.0-cil libglibmm-2.4-1c2a libgmime-2.0-2 libgmime2.2-cil libgnome-desktop-2 libgnome-keyring0 libgnome-mag2 libgnome-media0 libgnome-menu2 libgnome-pilot2 libgnome-speech7 libgnome-vfs2.0-cil libgnome-window-settings1 libgnome2-0 libgnome2-canvas-perl libgnome2-common libgnome2-perl libgnome2-vfs-perl libgnome2.0-cil libgnomecanvas2-0 libgnomecanvas2-common libgnomecups1.0-1 libgnomekbd-common libgnomekbd2 libgnomekbdui2 libgnomeprint2.2-0 libgnomeprint2.2-data libgnomeprintui2.2-0 libgnomeprintui2.2-common libgnomeui-0 libgnomeui-common libgnomevfs2-0 libgnomevfs2-bin libgnomevfs2-common libgnomevfs2-extra libgpod3 libgtk-vnc-1.0-0 libgtk2-perl libgtk2.0-bin libgtk2.0-cil libgtkhtml2-0 libgtkhtml3.14-19 libgtkhtml3.16-cil libgtkmm-2.4-1c2a libgtksourceview-common libgtksourceview1.0-0 libgtksourceview2.0-0 libgtksourceview2.0-common libgtkspell0 libgtop2-7 libgtop2-common libgucharmap6 libguile-ltdl-1 libgvfscommon0 libgweather-common libgweather1 libhesiod0 libidl0 libiec61883-0 libkpathsea4 liblaunchpad-integration1 liblircclient0 liblpint-bonobo0 libmetacity0 libmono-addins-gui0.2-cil libmono-addins0.2-cil libmono-cairo1.0-cil libmono-corlib1.0-cil libmono-corlib2.0-cil libmono-data-tds1.0-cil libmono-data-tds2.0-cil libmono-security1.0-cil libmono-security2.0-cil libmono-sharpzip0.84-cil libmono-sharpzip2.84-cil libmono-sqlite2.0-cil libmono-system-data1.0-cil libmono-system-data2.0-cil libmono-system-web1.0-cil libmono-system-web2.0-cil libmono-system1.0-cil libmono-system2.0-cil libmono0 libmono1.0-cil libmono2.0-cil libnautilus-burn4 libnautilus-extension1 libndesk-dbus-glib1.0-cil libndesk-dbus1.0-cil libnet-dbus-perl libnm-glib0 libnotify1 liboil0.3 liboobs-1-4 libopal-2.2 libopenal0a liborbit2 libotr2 libpam-gnome-keyring libpanel-applet2-0 libpisock9 libpisync1 libpolkit-gnome0 libpoppler-glib2 libportaudio0 libpt-1.10.10 libpt-1.10.10-plugins-alsa libpt-1.10.10-plugins-v4l libpt-1.10.10-plugins-v4l2 libpulse-browse0 libpulsecore5 libpurple0 libqthreads-12 librarian0 librsvg2-common libscrollkeeper0 libsexy2 libshout3 libsndfile1 libsoup2.4-1 libsqlite0 libstartup-notification0 libtotem-plparser10 libtracker-gtk0 libtrackerclient0 libvte-common libvte9 libwnck-common libwnck22 libx11-xcb1 libxevie1 libxklavier12 libxml-twig-perl libxml2-utils libxres1 libzephyr3 mesa-utils metacity metacity-common mono-common mono-gac mono-jit mono-runtime mousetweaks nautilus nautilus-cd-burner nautilus-data nautilus-sendto nautilus-share network-manager-gnome notification-daemon o3read obex-data-server onboard openoffice.org-gnome openoffice.org-gtk pidgin pidgin-data pidgin-otr pkg-config policykit-gnome pulseaudio pulseaudio-esound-compat pulseaudio-module-gconf pulseaudio-module-hal pulseaudio-module-x11 pulseaudio-utils python-brlapi python-cairo python-gconf python-gdata python-glade2 python-gmenu python-gnome2 python-gnome2-desktop python-gnomecanvas python-gst0.10 python-gtk2 python-gtkhtml2 python-gtksourceview2 python-launchpad-integration python-notify python-numeric python-pyatspi python-pyorbit python-sexy python-virtkey python-vte rhythmbox rss-glx scim scim-bridge-client-gtk scim-gtk2-immodule screensaver-default-images scrollkeeper seahorse sgml-base sgml-data shared-mime-info software-properties-gtk sound-juicer sqlite sqlite3 ssh-askpass-gnome synaptic system-config-printer-gnome system-tools-backends tangerine-icon-theme tomboy totem totem-common totem-gstreamer totem-mozilla totem-plugins tracker tracker-search-tool transmission-common transmission-gtk tsclient ubufox ubuntu-artwork ubuntu-desktop ubuntu-docs ubuntu-gdm-themes ubuntu-sounds ubuntu-wallpapers update-manager update-notifier usplash-theme-ubuntu vinagre vino whois xdg-user-dirs-gtk xml-core xsane xsane-common xscreensaver-data xscreensaver-gl xsltproc xulrunner-1.9 xulrunner-1.9-gnome-support yelp zenity && sudo apt-get install kubuntu-desktop

Lo mismo puedes hacer si quieres borrar Kubuntu o Xubuntu completamente.

Borrar Kubuntu (KDE) (instalando GNOME)

sudo apt-get remove adept adept-batch adept-common adept-installer adept-manager adept-notifier adept-updater akregator amarok amarok-xine apport-qt ark arts cryptsetup debtags desktop-effects-kde digikam dmsetup dolphin enscript foomatic-db-gutenprint gdebi-kde gnupg-agent gpgsm gtk-qt-engine gwenview hpijs-ppds hplip-gui ijsgutenprint jockey-kde k3b kaddressbook kaffeine kamera karm katapult kate kbstate kcontrol kcron kde-guidance kde-guidance-powermanager kde-icons-mono kde-style-qtcurve kde-systemsettings kdeadmin-kfile-plugins kdebase-bin kdebase-bin-kde3 kdebase-data kdebase-kio-plugins kdebluetooth kdegraphics-kfile-plugins kdelibs-data kdelibs4c2a kdemultimedia-kfile-plugins kdemultimedia-kio-plugins kdenetwork-filesharing kdenetwork-kfile-plugins kdepasswd kdepim-kio-plugins kdepim-kresources kdepim-wizards kdeprint kdesktop kdesudo kdm kdnssd keep kfind kghostview khelpcenter kicker kio-apt kio-locate kio-umountwrapper kipi-plugins klipper kmag kmail kmailcvt kmenuedit kmilo kmix kmousetool kmplayer-base kmplayer-konq-plugins knetworkconf knotes konq-plugins konqueror konqueror-nsplugins konsole kontact konversation kooka kopete korganizer kpdf kpf kppp krdc krfb kscreensaver ksmserver ksnapshot ksvg ksysguard ksysguardd ksystemlog ktorrent kubuntu-artwork-usplash kubuntu-default-settings kubuntu-desktop kubuntu-docs kubuntu-konqueror-shortcuts kvkbd kwalletmanager kwin kwin-style-crystal language-selector-qt libakode2 libarts1-akode libarts1c2a libartsc0 libaudio2 libavahi-qt3-1 libavcodec1d libavutil1d libclucene0ldbl libdbus-qt-1-1c2 libept0 libexiv2-2 libfftw3-3 libflac++6 libgmp3c2 libgsm1 libifp4 libijs-0.35 libjpeg-progs libk3b2 libkbluetooth0 libkcal2b libkcddb1 libkdcraw3 libkdepim1a libkexiv2-3 libkipi0 libkleopatra1 libkmime2 libkonq4 libkpimexchange1 libkpimidentities1 libksba8 libkscan1 libksieve0 libktnef1 liblua50 liblualib50 libmad0 libmimelib1c2a libmodplug0c2 libmpcdec3 libnjb5 libofa0 libpoppler-qt2 libpostproc1d libpq5 libpythonize0 libqt-perl libqt3-mt libqt4-core libqt4-gui librsync1 libruby1.8 libsearchclient0 libskim0 libsmokeqt1 libstreamanalyzer0 libstreams0 libstrigihtmlgui0 libtunepimp5 libxapian15 libxcb-shape0 libxcb-shm0 libxcb-xv0 libxine1 libxine1-bin libxine1-console libxine1-ffmpeg libxine1-misc-plugins libxine1-plugins libxine1-x libxvmc1 network-manager-kde networkstatus openoffice.org-kde openoffice.org-style-crystal perl-suid pinentry-qt poster psutils pykdeextensions python-dev python-kde3 python-qt3 python-qt4 python-qt4-common python-qt4-dbus python-reportlab python-sip4 python2.5-dev qca-tls rdiff-backup ruby ruby1.8 scim-bridge-client-qt scim-qtimm skim software-properties-kde speedcrunch strigi-applet strigi-daemon system-config-printer-kde ttf-arphic-ukai vorbis-tools && sudo apt-get install ubuntu-desktop

Borrar Xubuntu (XFCE) (instalando GNOME)

>sudo apt-get remove a2ps abiword abiword-common abiword-plugins gnumeric-common gnumeric-gtk gtk2-engines-xfce imagemagick libaiksaurus-1.2-0c2a libaiksaurus-1.2-data libaiksaurusgtk-1.2-0c2a libexo-0.3-0 libgdome2-0 libgdome2-cpp-smart0c2a libglib2.0-data libgoffice-0-6 libgoffice-0-6-common libgsf-gnome-1-114 libgtkmathview0c2a liblink-grammar4 libots0 libt1-5 libtagc0 libthunar-vfs-1-2 libwpd-stream8c2a libxfce4mcs-client3 libxfce4mcs-manager3 libxfce4util4 libxfcegui4-4 link-grammar-dictionaries-en mousepad mozilla-thunderbird orage psutils python-exo ristretto tango-icon-theme tango-icon-theme-common thunar thunar-archive-plugin thunar-data thunar-media-tags-plugin thunar-thumbnailers thunar-volman thunderbird vim-runtime xfce4-appfinder xfce4-battery-plugin xfce4-clipman-plugin xfce4-cpugraph-plugin xfce4-dict-plugin xfce4-fsguard-plugin xfce4-governor-plugin xfce4-icon-theme xfce4-mailwatch-plugin xfce4-mcs-manager xfce4-mcs-plugins xfce4-mcs-plugins-extra xfce4-mixer xfce4-mixer-alsa xfce4-mount-plugin xfce4-netload-plugin xfce4-notes-plugin xfce4-panel xfce4-places-plugin xfce4-quicklauncher-plugin xfce4-screenshooter-plugin xfce4-session xfce4-smartbookmark-plugin xfce4-systemload-plugin xfce4-terminal xfce4-utils xfce4-verve-plugin xfce4-weather-plugin xfce4-xkb-plugin xfdesktop4 xfdesktop4-data xfprint4 xfwm4 xfwm4-themes xubuntu-artwork-usplash xubuntu-default-settings xubuntu-desktop xubuntu-docs && sudo apt-get install ubuntu-desktop

Nota: Al final del supercomando debes añadir: && sudo aptitude install (xubuntu-desktop o ubuntu-desktop o kubuntu-desktop)

Eligiendo el entorno, por ejemplo, si quiero pasar de GNOME a KDE (Kubuntu) utilizaría el comando borrar Ubuntu GNOME y le añadiría al final: && sudo aptitude install kubuntu-desktop y ya tendría un KDE sin “restos” de otros escritorios.

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