Have you installed a fresh Ubuntu? If YES! then you might be experiencing a few problems in listening to the music, watching videos and surfing the web as in problems with Flash, Java and so on. Don’t worry just feed your terminal with the following commands and all will be well. 😀 This is just because the patent and copyright restrictions (see Ubuntu License Policy) complicate distribution of software to support non-free formats.
sudo apt-get install ubuntu-restricted-extras
sudo apt-get install kubuntu-restricted-extras
sudo apt-get install lubuntu-restricted-extras
sudo apt-get install xubuntu-restricted-extras
To play DVDs, you need to install libdvdcss by entering the following in a terminal: