Hi, my friend. If your Windows 11 boots into the "please enter BitLocker recovery key" screen, you can launch the Command Prompt to run specified command lines to eliminate this issue, and then you can benefit from the Secure Boot DBX.
If the BitLocker Group Policy Configure TPM platform validation profile for native UEFI firmware configurations is enabled and PCR7 is selected by policy, which may result in the update failing to install. Don't worry just yet, you can rule out the issue by running the following command lines:
Case 1: You haven't enabled Credential Gard on your device
On a device that does not have Credential Gard enabled, run the following command from an Administrator command prompt to suspend BitLocker for 1 restart cycle:Manage-bde –Protectors –Disable C: -RebootCount 1
Then, you can restart the update and reboot your device to resume the BitLocker protection.
Case 2: You have enabled Credential Gard on your device
On a device that has Credential Guard enabled, run the following command from an Administrator command prompt to suspend BitLocker for 2 restart cycles:Manage-bde –Protectors –Disable C: -RebootCount 3
Then, you can deploy the update and restart the device to resume the BitLocker protection.
This security update makes improvements to Secure Boot DBX for the supported Windows versions listed in the "Applies to" section. There are crucial enhancements, and you can have a rough understanding:
1. Windows devices that have Unified Extensible Firmware Interface (UEFI) based firmware can run with Secure Boot enabled. The Secure Boot Forbidden Signature Database (DBX) prevents UEFI modules from loading. This update adds modules to the DBX.
2. A security feature bypass vulnerability exists in secure boot. An attacker who successfully exploited the vulnerability might bypass secure boot and load untrusted software.
3. This security update addresses the vulnerability by adding the signatures of the known vulnerable UEFI modules to the DBX.
Furthermore, having the BitLocker recovery key on hand at all times is essential for dealing with emergency situations. If you have no password nor BitLocker Recovery key, read our relevant article: How to Bypass BitLocker Recovery Screen Asking Recovery Key?