Security update error KB958644

[Tamas0513]

Dear All,

when running the Windows Update service (both automatic or manual) one part of the update won't install at all, and the "Security Update for the x64-based Windows Vista system edition (KB958644) install failure Error code:800B0100" message received when I check the installed updates. Update info said this is an important update.

I have Vista Business 64-bit SP2. Everything is working properly, so this is not a reason of rescue, but I hate this error messages at updates.

Can you have any idea what's wrong and suggest a solution? I've tried every steps from Microsoft Support, but without success.

Thanks in advance!
Tamas