If you need to transfer files to and from PGP Encryption Server, you will need to use SCP with key based authentication.
If you are happy to use a command line utility, you can use the utility included with PuTTY or the one included with OpenSSH for Windows. Please see article 153592 - Access the PGP Encryption Server by using SSH (Symantec Encryption Management Server) for details.
If you wish to use a graphical Windows application you can use the open source WinSCP application or the free FileZilla application. This article outlines how to use WinSCP.
PGP Encryption Server 3.4.2 and above.
Before you begin, you will need to have created a public and private SSH key and to have imported the public key into PGP Encryption Server. Please see article 153592 - Access the PGP Encryption Server by using SSH (Symantec Encryption Management Server) for details.