In order to narrow down the cause of our issue, let's refer to the following
steps:
NOTE: Some third party programs can affect the Windows Update service. If
you are running any third party applications such as Spyblocker, Internet or
web accelerators (programs designed to boost the speed of the Internet
connection), security or anti-virus programs (Norton, McAfee, etc.), I
recommend we temporarily disable or shut them down and then try to access the
Windows Update site later. Please be sure to enable them again when the
update process has been completed.
Download and install the update manually.
==========================
1. Please visit the following link and download the update
Security Update for Windows Vista (KB943055
http://www.microsoft.com/downloads/d...DisplayLang=en
Security Update for Windows Vista (KB946456
http://www.microsoft.com/downloads/d...DisplayLang=en
2. Please note its location and install it manually.