LiveUpdate checks for updates to the product that is installed on your computer.
These updates protect your computer from newly discovered threats. LiveUpdate uses the Internet connection to connect to the Symantec server, checks for updates, and then downloads and installs them automatically.
You should have Automatic LiveUpdate turned on to ensure that you have the latest definition updates and program updates. Definition updates contain the information that allows the product to recognize and alert you to the presence of a specific virus or security threat. Symantec issues program updates periodically, which are enhancements to the product. Program updates usually contain changes to the inner workings of the program. After you install program updates, you might not necessarily see a difference in the way that the product works.

If you are not connected to the Internet, connect to the Internet first, and then run LiveUpdate. Or, if you use a proxy server to connect to the Internet, configure the proxy settings, and then run LiveUpdate. You can configure the Network Proxy Settings options in the Miscellaneous Settings section in the Settings window.