BitLocker dropping into recovery mode after hypervisor updates

Question

BitLocker dropping into recovery mode after hypervisor updates

Islada Vies 0

BitLocker drops straight into recovery mode on startup every time we apply hypervisor security updates

because the update alters the PCR 11 measurement logs.

I would like to know how to suspend BitLocker prior to system updates and refresh the PCR baseline logs please.

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Answer 1

Hello Islada Vies,

When hypervisor security updates modify launch binaries or code integrity policies, the measurements extended into PCR 11 change, invalidating the TPM sealed key and prompting BitLocker recovery. To avoid this interruption during servicing windows, you can temporarily suspend BitLocker protection so the system boots using an unsealed clear key while committing new measurements.

Before applying updates, run Suspend-BitLocker -MountPoint C: -RebootCount 1 from an elevated PowerShell console, or manage_bde -protectors -disable C: -RebootCount 1. This keeps protection suspended across the immediate hypervisor restart. Once the updates finish installing and the machine reboots into the updated hypervisor state, BitLocker automatically resumes and reseals the volume master key against the updated PCR 11 baseline.

If protection does not resume automatically or you need to force a clean reseal, execute Resume-BitLocker -MountPoint C: to commit the current TPM measurements. If this guidance successfully prevents recovery mode prompts during your updates, please accept the answer.

Tracy Le.