After trying several times to do a Microsoft Update on a win2k machine
(with SP4 already installed), it fails doing either an EXPRESS or CUSTOM
install.

This seems to be preventing me being able to update the machine entirely.

Sequence of events, after choosing EXPRESS install:

First window says:
Updates were unable to be successfully installed

The following updates were not installed:
Microsoft Windows Installer 3.1
Windows Genuion Advantage Validation Tool (KB892130)
[Close]

Hit 'Close', new window says:
Failed updates.
For help installing an update successfully, see the solution under each
problem subscription.

Problem: Please "check your update history" [link] for a description.
o Microsoft Windows Installer 3.1
o Windows Genuine Advantage Validation Tool (KB892130)

And when I check the update history table and find the failed item,
none of the links work for that item to show the error. The entry is:

Product: Windows
Update: 816093: Security Update Microsoft Virtual Machine (Microsoft VM)
Status: [X logo and a "?"]

Clicking any of the links for that item has no effect; no windows open,
no text is displayed.

I'm at a loss as to know how to procede, as there are no error reporting
details.

I have Norton Antivirus disabled during the update.