If you have Windows BitLocker Drive Encryption (BDE) enabled on your system, it is recommended that BDE be suspended temporarily before the BIOS is updated. You should also obtain your BDE recovery password or recovery PIN before suspending BDE. After the BIOS is flashed, BDE can be resumed.
To make a change to BDE, select Start > Control Panel > BitLocker Drive Encryption, click ‘Suspend Protection’ or ‘Resume Protection’ and then click ‘Yes’.
If you use HPBIOSUPDREC to update your BIOS in Windows, the application will attempt to suspend Bitlocker for you while the BIOS update is in progress.
As a general rule, updating the BIOS will modify measurement values stored in the Platform Configuration Registers (PCRs) of the system’s security module (TPM). Technologies that use these PCR values to ascertain platform health (BDE is one such example) should be temporarily disabled prior to flashing the BIOS. Once the BIOS is updated, the functions should be re-enabled and the system should be restarted so that new measurements can be taken