What I got was a very fast (17-second) boot to my desktop (Eeewww! Ugly at 640 x 480 resolution or whatever) and every one of the applications available in Safe Boot mode ran instantly and normally.

Here are some additional bits of data.

I can verify that the problem began immediately after the update. I remember because the very first time I saw the fancy new Windows 10 splash screen (rocks and ocean waves, a quite nice photograph) was when I couldn't get anything to run.

About the only inconsistency in the stalled reboot is that sometimes Windows File Explorer works properly immediately on bootup, usually it does not. When it does work properly, the directory tree displays are practically instantaneous across all four hard drives, even though nothing else will run, so I don't think it is a problem of CPU overload.

From display of the desktop to having functional programs took six minutes and fifty two seconds that last time I tried it.

Is it possible that this update is unhappy because my system drive is an SSD, not a mechanical drive?

Unless someone here can suggest a simple and quick fix for this, I am going to decide this is "above my pay grade" so to speak, and bundle the computer up and take it to the local shop that built it for me. They are reasonably technically competent (FAR more than I am) and quite inexpensive - I anticipate about a $500 peso repair bill, about $35 USD at the current exchange rate. I don't have the skills and especially not the patience, what with a seven-minute reboot every time I change something, to deal with this myself.

tanstaafl.