After a number of boots, I have seen no SCM hangs. I have been clearing my prefetch before I shutdown. I will get brave enough to let the prefetch go one of these days.
Checking the option Vlk suggested prompts the obvious question:
What is the downside of this option? If there is none, why is 'Delay loading....' not the default?
Thanks again to Vlk and Tech........JohnHC