When you attempt to turn on BitLocker for the first time, you might receive an error message stating that your basic input/output system (BIOS) must be updated before you can use BitLocker. This is because the computer was manufactured with the Trusted Platform Module (TPM) security hardware (a special microchip in some newer computers that supports advanced security features), version 1.2 or higher, and your computer's BIOS needs an update to work properly with TPM. You should only receive this error message if you upgraded to this version of Windows from a previous Windows operating system.
Procedures for updating the BIOS vary depending on the manufacturer. Check the information that came with your computer or go to the computer manufacturer's website.
If you've already turned on BitLocker and need to update the BIOS for another reason, such as solving a hardware compatibility problem, temporarily disable BitLocker before updating the BIOS, and then turn BitLocker back on when the update is complete. This prevents BitLocker from locking the drive Windows is installed on when you restart the computer after the update.
Updating the BIOS is an advanced procedure, and if an error occurs, your computer could become inoperative. Be sure to follow the manufacturer's instructions exactly.
Assistive technology software that runs on Windows, such as screen reading software, cannot read BitLocker startup screens because they are displayed during BIOS startup and before Windows runs. This includes screens used when you type a PIN or recovery password, and any BitLocker error messages.