You are using Symantec Endpoint Protection with a managed Host Integrity policy that requires the installation of a Microsoft patch. The Host Integrity policy is configured to install the patch if it is not found on the target system, and to run the patch installer "in system context" (rather than under the username that is currently logged in). The patch is not installed.
The patch will install if "logged-in user context" is chosen instead.
This is because the patch installer cannot request user interaction when running in the system context on Windows Vista.
To work around this problem, add the /quiet switch to the patch installer.
wusa.exe /quiet d:\downloaded\Windows6.0-KB925528-x64.msu