Hi,I'm having some trouble encrypting a drive using Bitlocker.I have the drive correctly partitioned and Bitlocker is recognising the correct drive to encrypt but when I try to encrypt it I get error messages as follows.On Boot:"Windows Bitlocker Drive Encryption Information-*The system boot information has changed since Bitlocker was enabled.**You must supply a Bitlocker recovery password to start this system.***Confirm the changes to the system boot information are authorised.****If the changes to thge system boot information are trusted, then disable and re-enable Bitlocker. This will reset Bitlocker to use the new boot information.*****Otherwise restore the system boot information"Ok so let's go through this. * To my knowledge the only changes I've made to the boot info is to change it to boot from the local HDD instead of the USB drive with the recovery info on.** Recovery password is on the USB drive.*** How do I do this??**** Again, how do I do this? I can't disable something which isn't actually enabled already.***** And yet again, how do I do this? If I keep the boot order the way it was, it won't be able to read off the USB drive.On Login:"Bitlocker Drive Encryption-The Trusted Platform Module (TPM) was not able to unlock the volume because the system boot information changed.No encryption applied, any changes made to C: during Bitlocker setup will be removed"So there you have it. Any help that anyone, anywhere can offer on this would be greatly appreciated as I REALLY need to encrypt this drive.Thanks.Steve

Should probably mention what I'm running.Sony Vaio VGN-G11XN/BTPM version - Manufacturer IFX version 1.0 Spec version 1.2Ownership is on and has been taken and TPM is initialised.Cheers.

Right,I've managed to sort this one out.The issue was with the TPM not allowing the Bitlocker Access Control. So do the following and it should work! gpedit.msc Administrative Templates Windows Components BitLocker Drive Encryption Disable by unchecking all PCR settings BUT 11 Start-->CMD [Enter] (in search) GPUpdate /force A screenshot of the GPEdit.msc changes: GPEdit.msc Vista TPM PCR Settings Edited Reboot the system, reinitialize the TPM and run the BitLocker Drive Encryption tool to create another key and encrypt the drive.You can test that the settings have taken by rebooting the system after pausing the encryption process at 1%. Note that a UAC prompt will happen after clicking the Pause button on the BitLocker encryption process window.Thanks.

This suggestion worked for me on Windows 7 Ultimate and Sony VGN-Z880G. Thanks!!