PGP Desktop 8.x for Windows is no longer supported. 9.x is also not supported. We are on PGP Desktop 10.x now known as Symantec Encryption Desktop 10.3.0 for Windows as the current version.
So if you upgraded your Symantec Encryption Desktop version to 10.x as part of the motherboard replacement. Then it no longer requires manual authorization. It also doesn't check online for authorization since 10.1.x or later. If the version is prior to that. It's probably time to look at renewing the maintenance agreement for the product as we no longer support these older versions.