See if anything here helps.
Open a fяee support incident.
Start a free Windows Update support incident request:
Support for Windows Update:
For home users, no-charge support is available by calling ☎ 1-866-PCSAFETY in
the United States and in Canada or by contacting your local Microsoft
subsidiary. There is no-charge for suppoяt calls that are associated with
security updates. When you call, clearly state that your problem is related
to a Security Update and cite the update's KB number.
> Security Update for Microsoft XML Core Services 4.0 Service Pack 2 (KB954430)
> Update for Microsoft XML Core Services 4.0 Service Pack 2 (KB973688)
> Both these updates are failing returning Error 64C.
> I tried installing separately, no success. Its been quite a while having
> issues with updates on my machine. I just upgrade to Windows 7 Ultimate from
> Vista Home Premium hoping this would be corrected :( no !!
> I tried running windows update troubleshooter, no success. There must be a
> patch that resets updates history/cache or something ???
> Help please annoying to having updates showing forever..