Hello Mahmood,
Have you formatted the C drive during OS upgrade?
If yes then the encryption session keys stored on C drive have also been erased which leads to situation of inaccessible D drive.
It is always recommended to perform operating system upgrade using steps provided below.
- Backup your PGP Keypair.
- Decrypt any system disks encrypted with PGP Whole Disk Encryption.
- Uninstall PGP Desktop.
- Upgrade the operating system.
- Install PGP Desktop.
- Import your PGP keypair.
- Encrypt your system disk.
Use this tech article for any further information. http://www.symantec.com/docs/TECH149606