Whoops, got another 3938,104! The system clock was about 15 seconds off time-a.nist.gov; corrected that and no joy. LiveUpdate runs OK. I verified that my logon has Adminstrator priveleges and went through the two-boot process involving Notification settings. QuickScan runs now but it always runs with just a reboot.
I'm out of ideas right now. What is the next step?
As long as I had to shut everything down and reboot, I'm goning to run NPE just to be absolutely sure that there is nothing in there.