Windows Automatic Updates not auto updating

[Kevin Shalla <kshalla () UIC EDU>]

We've set up Windows Automatic Update to automatically download and
install updates every day, and have found that some updates still
won't go without manual intervention.  In particular, we've found
that some were still waiting for XP service pack 2!  In the lower
right-hand corner there is an icon that says (if you mouse over) that
updates are ready to be installed, but our users don't look at that,
so they don't get installed.  Is there a way to set up Windows
Automatic Update to install updates without any input required?