I can go to Windows Update, but when trying to update XP (Pro, 32 bit) it
will download, then say the install is starting. But the installation will
fail.

Then when I reboot it will say Install Updates and Shut Down. It installs
properly (if I go back into Windows Update it will say I have installed
those updates already).

However, if I install Optional Components these will not trigger the
"Install Updates and Shut Down" Reboot option. I usually have to install
these manually.

This only happens on ONE PC (Dell Inspiron XPS Gen 2). All my others work
normally. This has been happening from the very beginning.

Any ideas?