Error updating windows vista service pack 1
KB2887535 as mentioned does not have a download link for Vista, and the 7 SP1 version did not work for me.
I had to download version 7.4 of the update agent (KB946928) which did install properly.
However, shortly after the installation starts the wizard disappears.
Windows Update says that the update was installed successfully.
However, service pack 1 is not in fact installed, and will be detected as needed again on the next update check. On checking the Windows Update log () the client version is 6.0.6000or 6.0.6001