To disable live update, there are two locations where the PolicyLiveUpdate key is kept:
32-bit: [HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\VIP Access Client]
64-bit: [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Symantec\VIP Access Client]
If your are using a 32-bit operating system, please check the location above to disable the updates via policy.