OK - if you are getting the error code, the problem is not WSUS--WSUS is a
server service which network admins can deploy to control which patches are
distributed within a corporate lan. If such a service is available, Windows
Defender goes there for its updates--and if they haven't been enabled, the
update fails silently.
That is NOT your problem, however, since you get that error number. I'm
sorry to have to say that I don't have a solution for that error message--I
believe there are approximately 3 people in these groups with that error at
the moment, and I don't have a fix for it.
I'd recommend re-posting to a new thread, and putting the error message
number in the subject header. Microsoft is reading these threads, even
today, which is a holiday in the U.S.--and maybe we can get an authoritative
response, if we can draw attention to that error code.
--