The first thing you should do is install any updates made available since Ubuntu was released. The easiest way of doing this is to click the Software Updater icon on the launcher or click the ubuntu button and searh for "update".
You may need to authorize the update with your
password if kernal updates are being installed.
Enable Audio & Video Playback After Installing Ubuntu
Ubuntu is freely available to download anywhere in the world, in order to accomplish this Ubuntu cannot distribute proprietary software such as audio and video codecs, which are not licensed for use in some countries.
This is easily resolved by installing
"Ubuntu Restricted Extras"
from Ubuntu Software Centre.
For Xubuntu, Kubuntu and Lubuntu
use their own restricted extras package
ie. "xubuntu restricted extras"
You can also install from a terminal using the command
sudo apt-get install ubuntu-restricted-extras
Install Additional Drivers
Prorietary drivers can be installed using the Additional Drivers
application, just click the Ubuntu button and search for "Drivers".