What configuration should be done to allow BitLocker to encrypt a hard disk and boot automatically without a startup key?

To allow BitLocker to encrypt a hard disk and enable automatic booting without the need for a startup key, enabling the Trusted Platform Module (TPM) in the BIOS is essential. The TPM is a hardware component that provides secure storage for cryptographic keys and other security-related functions.

When TPM is enabled, it allows BitLocker to automatically unlock the encrypted drive without requiring a startup key or PIN during boot. This is because the TPM can verify the integrity of the system upon startup and release the encryption keys to allow the operating system to boot securely. This feature provides a balance of security and convenience, as the user can access their system without additional input while still protecting the data on the hard drive.

Other options do not achieve the goal of enabling automatic boot without a startup key effectively. Saving the startup key to the boot partition does not eliminate the need for a key; it simply stores it on the disk. Using a PIN instead of a startup key introduces an additional step rather than bypassing it. Disabling USB devices in the BIOS does not relate to BitLocker or its ability to allow automated boot processes; rather, it may affect boot operations if critical USB components are disabled.