A solution:

The notebook is a Toshiba with a P4 at 3gbs +/-.

After umpteen startups and lockups today after an update that required
restart. The escape key would not escape it.

So, just for grins I went into the setup several times. The last time, I
noticed a setting for "2nd Logical Processor." I've noticed some software
that behaves as if the computer has two processors. I set this to disable
and restarted. The disk check ran flawlessly and took less than a minute.

Now testing, BOINC now runs only one instance. So I may change it back, or
not, depending what else I may be able to determine.