My understanding is that WinPE (Microsoft, not Symantec) always tries to load various drivers. I suggest load the correct ones and see if it helps.
As for the live update, you could install it on another PC that has internet access and then there should be files put on the desktop if I remember right (it's been a while). Copy those files over to the other PC and run them that way.
As far as a direct download I remember this being discussed about a year ago but I don't recall the result, if you do some searching on these forums you should be able to find it.