Hi Liu Zhe,
Is the secondary disk showing up under PGP Disk on Symantec Encryption Desktop?
While trying to access the disk are you getting any error message?
Under Disk management is the Disk listed, and what is the status showing up there?
You can try decrypting the drive from command prompt using the command pgpwde –decrypt – disk 1 –p “PASSWORD”, this command need to be ran browsing to the PGP Desktop folder.
Please check the PGP Command Line 10.3.2 User's Guide
www.symantec.com/docs/DOC7066