I have tried many things, like downloading it manually. I have read other forums, who say to uninstall the existing 954430 update (in Add or Remove Programs) and reinstall. There is no existing one.
When I install manually, it comes back with an error message: HKEY_LOCAL_MACHINE\Software\Classes\MSXML2.DOMDocument.4.0\CLSID verify that you have sufficient access to that key.
Help! I am trying to install SP3, and it will refuse that, too, because an update is not installed.
I am just running a plain version of Windows XP Home.