This article describes how to add existing keyring files to PGP Encryption Desktop Windows.
153196 - Backup/Export PGP Keypairs
180129 - Accessing the Backup Keyrings Created Automatically by PGP Encryption Desktop for Windows
180128 - Import a Keypair into PGP Encryption Desktop (Windows)
180130 - Reconstructing Your Private Key with PGP Encryption Desktop for Windows
153511 - Additional Decryption Key (ADK) Guidelines for Symantec Encryption Management Server
153477 - Import an ADK to Symantec Encryption Management Server (aka PGP Universal Server)