Here's a list of things you can do, from Symantec:
http://service1.symantec.com/SUPPORT...e=&svy=&csm=no
That's multi-line, so you'll need to paste the whole thin, or if it doesn't work, try going to Symantec.com, click on support, go to the home & small office part, then on the bottom, where you can search documents, enter "running liveupdate doesn't update virus definitions"