Windows Update won't complete

[Dick]

After installing critical updates, I am trying to install
other XP updates, like DirectX, error reporting etc.

Any attempt results in download completion, then hang
while "Installing Updates" Same if I try one at a time
or several.

I turned off McAffee and see no change.

Curiously, on shutdown, the system goes through logging
off then hangs at "shutting down". could be related, or
not.

Help please?