Since the system has never successfully updated you can follow the steps
laid out here: http://support.microsoft.com/kb/934562
After renaming the SoftwareDistribution folder, restart the system to
normal Windows mode.
Download and SAVE the latest version of the Windows Update Agent [WUA]
for the version of Vista that is installed on the system :
Windows Update Agent 3.0 [x86 - 32 bit]
http://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x86.exe
Windows Update Agent 3.0 [x64 or 64 bit]
http://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x64.exe
When the download completes close the browser and any other open programs.
Now install the WUA.
Did that help ?
MowGreen [MVP 2003-2007]
===============
*-343-* FDNY
Never Forgotten
===============