This document explains how to use LiveUpdate to obtain the latest virus definitions from Symantec.
Click the yellow and black Symantec icon in the menu bar.
Select LiveUpdate, then Open LiveUpdate.
In the LiveUpdate window, click Update Now.
LiveUpdate will check with Symantec's servers, determine whether any updates are available, download the updates, and install them.
Once everything is finished, you will see a summary page. Click Ok to return to the LiveUpdate window or Quit to exit LiveUpdate.