Procedure for fixing Norton/Symantec LiveUpdate. Problems with this can cause long delays when the machine is first booted up, or errors like...

"LiveUpdate had an internal error while getting your updates. Your Symantec programs were not updated. You should try getting updates at a later time. If LiveUpdate fails again with this error, you should re-install LiveUpdate."

http://helpdesk.its.uiowa.edu/virus/troubleshooting/lufix.htm

1. Before deleting the LiveUpdate directory, you should first obtain the lusetup.exe file. It is often included within the LiveUpdate directory at C:\Program Files\Symantec\LiveUpdate\lusetup.exe. You should copy this file to another directory or onto your desktop for use later in this procedure. In other words, you are copying a file from the directory you are about to delete.
   NOTE: If the file lusetup.exe is not present in the above directory, you may download it here.
   
2. The next step is to delete everything inside the folder C:\Program Files\Symantec\LiveUpdate. As long as you have access to the lusetup.exe file, this is safe because the lusetup.exe file will replace these files. You may either browse to this directory, highlight all the files and click delete or click on one file in that directory, press Ctrl+A and press the delete key.
   
3. Now you may run the lusetup.exe file that you copied to another directory in step 1. This will reinstall LiveUpdate onto your computer and, most importantly, replace the offending file(s) that were causing the error. When the lusetup.exe program finishes, click Finish or OK.
   
4. LiveUpdate should now be reinstalled and operational. You may test this by opening the Symantec/Norton AntiVirus console and clicking the LiveUpdate button.