Problem unpacking Security Essentials Desktop 10.3.0

Anybody,

My Boss (first name on the door) is getting an error installing the latest version of PGP (Security Essentials).
Here are the steps and the results:
Unpacks Zip to a local directory on laptop
runs the install from the unpacked location
gets the following
***************
Good Signature
SymantecEncryptionDesktop10.3.0_Windows_Inner.zip PGP Corporation Release Key <release-key@pgp.com> OxFA85DOOF
Invalid Key
12/10/2012 3:51:44 PM (Invalid Key)
***************
What "Key" is needed for this, or is there a more nefarious situation that I need to address?
Is there a particular way the install needs to be run if the machine already has Desktop 10.2.x MPx ??