|SGuard.msi is not a file built into Windows. It's a Windows Installer software package file for a third party program. Windows probably can't find it because it has been deleted. There are several possible programs that have a SGuard.msi file for them.|
What's the rest of the message ?
(window title:) "Sonic Update Manager
The feature you are trying to use is on a
network resource that is unavailable."
"I found out that the 'SGuard' refers to StorageGuard, a free data backup app (made by Stomp Inc.) that was installed along with RecordNow Max..."
"I determined it has something to do with either Veritas or Recordnow."
If it says (window title:) "Sonic Update Manager......
and if you have Roxio software installed, see this:
Update Manager (Service) issues and resolutions