After decrypting a disk encrypted with Symantec Drive Encryption, when rebooting you are prompted to enter your passphrase.
Although the hard drive was decrypted, the hard drive is still booting using the PGPMBR or is instrumented by PGP BootGuard and requires a passphrase for authentication.
In most cases, the disk appears instrumented after decryption when one of the encrypted partitions becomes inaccessible. You can verify this from the Windows Disk Management Utility that shows one of the partitions as Raw.
Resolution(s)
Uninstrument the drive in question to remove PGP BootGuard instrumentation from the specified disk. To do this, use the following procedures.
Determine if the hard drive is still encrypted or instrumented by Symantec Drive Encryption:
This command shows the current drives detected by Symantec Drive Encryption. The disks are labeled as Disk 0, Disk 1, Disk 2 and so on. Disk 0 is typically the boot volume or drive.
For the disk that you believe is encrypted by Symantec Drive Encryption, type pgpwde --status --disk 0 (or the disk number in question) and press Enter. This command shows the status of the disk. If the drive is still encrypted or partially encrypted, it lists a high-water mark value for the disk. The high-water mark depicts how many sectors are encrypted. If no disk with high-water mark is listed, and the message "Disk 0 is instrumented by bootguard" appears, then you need to uninstrument the disk.
If the disk still displays a high-water mark, you still have to decrypt the drive. If the Symantec Encryption Desktop graphical interface does not allow you to decrypt, you can decrypt from a command line. Use the command line interface only if the Symantec Encryption Desktop does not allow you to enter a passphrase and decrypt.
Caution: If any fixed disks are encrypted, decrypt them before you uninstrument disk 0. Symantec Drive Encryption does not know if required system files exist on other fixed disks. Therefore, when any fixed disk is encrypted, the main boot disk is instrumented as well. Before you uninstrument the boot disk, other disks should be decrypted.
Decrypting from a Command Line
Uninstrumenting your system
Uninstrumenting the disk using bootg.iso
Note: You might need to format the partition before being able to use it again.