SBS 2008 and Backup Exec - SP3 Install Error

I was installing Backup Exec 12.5d onto a SBS 2008 Premium Server and ran into an error.

Error: "LU1812: An update failed to install. A program that was part of this update failed . . . " when running LiveUpdate

This pointed to

http://service1.symantec.com/support/sharedtech.nsf/docid/2005072716150213?OpenDocument&seg=hho&src=_mi&product=LU&version=3.3&language=english&module=LU&error=1812&build=Symantec

After much contemplating my navel, installing the MSXML 3 SP7 and all the rest, I closed Backup Exec, right clicked on the Backup Exec icon and selected run as Administrator.

Service Pack installed..

Hope this helps someone.