Cant boot VM after enabling Bitlocker.

Hi Dalton Murray,

You enabled BitLocker on your Azure VM OS disk, configured it to optionally prompt for a BitLocker password at boot.

But now the VM boots, stalls at the BitLocker prompt (which you can't see remotely), then shuts down or becomes unreachable — because neither RDP, Bastian, nor Serial Console can intercept that pre-boot environment prompt.

Since you can’t boot into it, the typical fix is to detach the encrypted OS disk, mount it as a data disk on a recovery VM, unlock it manually, and recover your files/configs.

Steps to Fix:

Stop the Problematic VM

In Azure Portal: Go to your VM → Stop (deallocate).

Detach the OS Disk

Go to Disks in Azure Portal.Find the OS disk attached to your VM.

Detach it from the VM.

Attach the OS Disk to a Recovery VM

Create a new temporary VM (same OS type/version as your original).

Go to this recovery VM’s Disks blade.

Add a data disk, and select the detached OS disk from your old VM.

SSH/RDP into the Recovery VM.Login normally.

Unlock the BitLocker Disk (Windows Example)

Open Command Prompt as Administrator or PowerShell and run:

 manage-bde -unlock E: -RecoveryPassword YOUR-RECOVERY-KEY

(replace E: with the correct disk letter once attached, and YOUR-RECOVERY-KEY with your BitLocker recovery key — hopefully stored in Azure AD, your key vault, or saved elsewhere when you enabled BitLocker).

Check the status:

manage-bde -status E:

Now you can browse and copy files off, or decrypt the disk if needed.

Recover Your Data

Either copy your files to the recovery VM or storage account or decrypt the disk fully and reattach it as an OS disk to a fresh VM (if possible).

Please refer the document:

https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/windows/troubleshoot-bitlocker-boot-error

If you found information helpful, please click "Upvote" on the post to let us know.

If the issue still persist, feel free to ask us we are happy to assist you.

Thank you.