Open a terminal
Applications > Accessories > Terminal
and run these commands one at a time and your password wont be shown when you type it in just type it in and hit enter.
This first one enables the medibuntu repository for restricted codecs and such
Remove any browser media player plugin you currently have installed (totem-mozilla is installed by default, but you may have installed mozilla-mplayer or mozilla-plugin-vlc) like this:
sudo wget --output-document=/etc/apt/sources.list.d/medibuntu.list http://www.medibuntu.org/sources.list.d/$(lsb_release -cs).list && sudo apt-get --quiet update && sudo apt-get --yes --quiet --allow-unauthenticated install medibuntu-keyring && sudo apt-get --quiet update
then for all the multimedia, mp3's, divx web player, and dvd playback
sudo apt-get remove totem-mozilla mozilla-mplayer mozilla-plugin-vlc
sudo apt-get install ubuntu-restricted-extras libdvdcss2 gecko-mediaplayer vlc
Next we want the sun version of Java since it works better and will pass the test on this page.
It will say there is an update available but the main thing is it works.
And to get rid of one package in the restricted extras that causes problems:
sudo apt-get ininstall sun-java6-jre sun-java6-plugin
ttf-mscorefonts-installer bug report
sudo apt-get purge ttf-mscorefonts-installer
And to install Flash (the same as going to the adobe website) just click this link if using 9.04 or up, then on OK
And you're done.
VLC Player will be in Applications > Sound and Video > VLC