Initializing the TPM Security hardware. Access denied.

Durring manual activation of Bitlocker in order to encrypt Operating system drive there is a message Access Denied.

To mention that TPM is already configured on the local machine. The reason why this message appears is that GPO is configured to write TPM Backup information in AD.

Here the question is that there is not enough permissions to write requested TPM information in AD.

In order to enable this there is an excellent article from MS Core Team:

http://blogs.technet.com/b/askcore/archive/2010/03/30/access-denied-error-0x80070005-message-when-initializing-tpm-for-bitlocker.aspx

If you follow this article and give enough permissions to SELF account then Bitlocker Encryption will continue.