When the Lubuntu Desktop is installed in Ubuntu 12.04, it installs several packages and libraries it requires as well as some optional packages. Not all these packages and libraries are uninstalled when you uninstall Lubuntu Desktop. Several packages (like abiword and chromium browser) do not get uninstalled.

Quick Uninstall

1) Open a terminal (instructions can be found here).

2) Enter the following command (it is very long and a single line):

sudo apt-get purge --auto-remove abiword abiword-common abiword-plugin-grammar abiword-plugin-mathview  ace-of-penguins audacious audacious-plugins audacious-plugins-data blueman  chromium-browser chromium-browser-l10n chromium-codecs-ffmpeg  elementary-icon-theme esound-common galculator gdebi gdebi-core  gecko-mediaplayer giblib1 gnome-icon-theme-full gnome-mplayer gnome-system-tools  gnome-time-admin gnumeric gnumeric-common gnumeric-doc gpicview  gtk2-engines-pixbuf guvcview hardinfo indicator-status-provider-pidgin leafpad  libaacs0 libabiword-2.9 libaudclient2 libaudcore1 libaudiofile1 libbinio1ldbl  libbluray1 libbs2b0 libcddb2 libcompfaceg1 libcue1 libencode-locale-perl  libept1.4.12 libesd0 libexo-1-0 libexo-common libexo-helpers  libfile-listing-perl libfluidsynth1 libfm-data libfm-gtk-data libfm-gtk1 libfm1  libfont-afm-perl libgdome2-0 libgdome2-cpp-smart0c2a libglade2-0 libgmlib0  libgmtk0 libgmtk0-data libgoffice-0.8-8 libgoffice-0.8-8-common libgringotts2  libgsf-1-114 libgsf-1-common libgtkmathview0c2a libguess1 libhtml-form-perl  libhtml-format-perl libhtml-parser-perl libhtml-tagset-perl libhtml-tree-perl  libhttp-cookies-perl libhttp-daemon-perl libhttp-date-perl libhttp-message-perl  libhttp-negotiate-perl libid3tag0 libimlib2 libio-socket-inet6-perl  libio-socket-ssl-perl libjpeg-progs libjpeg-turbo-progs liblink-grammar4  libloudmouth1-0 liblwp-mediatypes-perl liblwp-protocol-https-perl  libmailtools-perl libmcrypt4 libmenu-cache1 libmowgli2 libmpg123-0  libnet-dbus-perl libnet-http-perl libnet-ssleay-perl libobrender27 libobt0  libonig2 liboobs-1-5 libopts25 libots0 libpisock9 libresid-builder0c2a  libsidplay2 libsocket6-perl libtar0 libtidy-0.99-0 libtie-ixhash-perl  libtimedate-perl libuniconf4.6 liburi-perl libvdpau1 libwebcam0 libwv-1.2-4  libwvstreams4.6-base libwvstreams4.6-extras libwww-perl libwww-robotrules-perl  libxfce4ui-1-0 libxfce4util-bin libxfce4util-common libxfce4util4 libxfconf-0-2  libxml-parser-perl libxml-twig-perl libxml-xpath-perl libxss1  lightdm-gtk-greeter link-grammar-dictionaries-en lm-sensors lubuntu-artwork  lubuntu-artwork-12-04 lubuntu-core lubuntu-default-settings lubuntu-desktop  lubuntu-icon-theme lubuntu-software-center lxappearance lxappearance-obconf  lxinput lxkeymap lxlauncher lxmenu-data lxpanel lxpanel-indicator-applet-plugin  lxrandr lxsession lxsession-edit lxshortcut lxtask lxterminal mplayer2 mtpaint  ntp obconf openbox openbox-themes osmo pcmanfm pidgin pidgin-data  pidgin-libnotify pidgin-microblog plymouth-theme-lubuntu-logo  plymouth-theme-lubuntu-text python-pysqlite2 python-xklavier scrot sylpheed  sylpheed-doc sylpheed-i18n sylpheed-plugins synaptic system-tools-backends  transmission ttf-lyx uvcdynctrl uvcdynctrl-data wvdial xfburn  xfce-keyboard-shortcuts xfce4-power-manager xfce4-power-manager-data xfconf  xfonts-100dpi xpad xscreensaver xscreensaver-data

It is easiest to copy the line and paste it into the terminal (right-click on the terminal and select Paste from the popup menu).

Preferred Uninstall

The better way to uninstall it is to follow the directions on this page.

This will show you on how to uninstall only the packages that were installed when Lubuntu Desktop was installed. The instructions are generic and work for any installed package.

It involves:

1. identifying which packages were installed and
2. creating a command to uninstall only those packages

It leaves intact any packages you may have installed (like abiword or chromium browser) or that were installed as dependencies for other programs instead of blindly assuming that they were installed along with Lubuntu Desktop.