Para dejar tu ubuntu fino una vez instalado solo tienes que ir al menu Aplicaciones -> Accesorios -> Terminal
Ahora copia y pega las siguientes ordenes ó comandos en el terminal, dale a intro, te pedira tu contraseña (escribela y pulsa intro aunque no se vea que escribe) una vez terminado tu ubuntu estara listo para funcionar con todos los codecs y programas mas comunes:
sudo wget http://www.medibuntu.org/sources.list.d/`lsb_release -cs`.list --output-document=/etc/apt/sources.list.d/medibuntu.list && sudo apt-get -q update && sudo apt-get --yes -q --allow-unauthenticated install medibuntu-keyring && sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"; sudo apt-get -q update
..mas opciones de tuneo en http://www.ubuntu-es.org/?q=node/131663 ..otras opciones de tuneo en http://www.glatelier.org/2010/04/despues-de-instalar-ubuntu-lucid-lynx-10-04/sudo aptitude install skype gparted build-essential linux-headers-`uname -r` flashplugin-nonfree flashplugin-nonfree-extrasound mplayer audacity vlc k3b audacious amarok avidemux qdvdauthor k9copy amule amsn pidgin compizconfig-settings-manager simple-ccsm gnome-art wine conky kaffeine gnome-themes-extras gxine me-tv kino devede lives mjpegtools nautilus-open-terminal cheese deborphan gdesklets screenlets gthumb emesene rar unace unrar p7zip p7zip-full arj dvdrip nicotine soundconverter pyrenamer libdvdcss2 w32codecs faad gstreamer0.10-ffmpeg gstreamer0.10-plugins-bad gstreamer0.10-plugins-ugly gstreamer0.10-pitfdll libmp3lame0 gbrainy recordmydesktop numlockx samba kompozer cmake mercurial mercurial-common nautilus-gksu mandvd vrms hddtemp avant-window-navigator openoffice.org-help-es openoffice.org-l10n-es openoffice.org-base clamtk hardinfo tucan googleearth gtkorphan bootchart vuze realplayer childsplay childsplay-alphabet-sounds-es pysycache gcompris stellarium tuxpaint celestia basic256 playonlinux acidrip ttf-droid pitivi jokosher moovida nrg2iso unace-nonfree unp sound-juicer alien debhelper html2text intltool-debian libmail-sendmail-perl librpm0 librpmbuild0 librpmio0 libsys-hostname-long-perl po-debconf rpm smartmontools python-statgrab ttf-liberation lm-sensors tesseract-ocr-spa gimp ntfs-config ubuntu-restricted-extras gstreamer0.10-plugins-ugly gstreamer0.10-plugins-ugly-multiverse gstreamer0.10-plugins-bad gstreamer0.10-plugins-bad-multiverse gstreamer0.10-ffmpeg gstreamer0.10-plugins-ugly gstreamer0.10-ffmpeg gstreamer0.10-pitfdll flashplugin-nonfree flashplugin-nonfree-extrasound unrar faad gstreamer0.10-ffmpeg gstreamer0.10-plugins-bad gstreamer0.10-plugins-bad-multiverse gstreamer0.10-plugins-ugly gstreamer0.10-plugins-ugly-multiverse gstreamer0.10-pitfdll mplayer w32codecs libdvdcss2 libdvdnav4 build-essential debhelper fakeroot flashplugin-nonfree ttf-mscorefonts-installer vlc wine audacious audacity inkscape filezilla k3b gmountiso ffmpeg mencoder sensors-applet lm-sensors checkgmail cheese ffmpeg2theora mencoder mplayer libogg-dev libvorbis-dev vorbis-tools ffmpeg imagemagick youtube-dl dvdauthor sox mjpegtools ffmpeg gddrescue dvdbackup ccd2iso nrg2iso mdf2iso bchunk transcode k3b kipi-plugins kommander lame faac flac simple-ccsm rar hoz hoz-gui mp3info flvtool2 ufraw id3 pdftk mpgtx pdfjam mp3splt nautilus-script-audio-convert nautilus-script-manager nautilus-script-debug x11vnc xtightvncviewer devede dvd95 oggconvert hwinfo sysinfo parcellite smbfs winff community-themes kdegraphics antiword unrtf odt2txt txt2tags cups-pdf disktype testdisk jokosher kdenlive avidemux winff dvdrip kaffeine k9copy mandvd mercurial seahorse docky chromium openshot miro diffuse libk3b6-extracodecs libk3b6 gimp gimp-data gimp-gap gimp-data-extras gimp-help-common gimp-help-es
…solución a los repositorios caidos: http://www.elblogderigo.info/2010/04/19/solucion-para-los-repositorios-caidos-de-medibuntu/