Cannot manually start AV

A person I know has a PC running Vista Business 32-bit with Norton AV.  I installed the OS and Norton, so I know everything worked at first.  However, if I double-click on the Norton desktop icon now, nothing happens; and nothing happens when I try to start it via the Start Menu.

 

I suspected malware, so I rebooted it and restarted in Safe Mode.  I ran a scan which completed with no problems found.  Strangely, I could not run LiveUpdate.  My only option seems to be to uninstall and reinstall it.

 

Isn't LiveUpdate supposed to run in Safe Mode?

 

Anyone have a guess as to why Norton would be non-responsive (other than malware)?