Event ID 24600 — BitLocker Startup

Applies To: Windows Server 2008 R2

When a computer protected with BitLocker Drive Encryption is restarted, the early startup components perform a series of integrity checks and, if the system passes, attempts to retrieve the needed key information to unlock any BitLocker-protected volumes. Success depends on the availability of configured key protectors, such as the TPM or a user-supplied PIN, and the existence of volume metadata stored within the encrypted drive.

If Windows cannot unlock the Windows operating system volume, BitLocker enters recovery mode. If the user can supply a recovery password or insert a USB flash drive with a recovery key, BitLocker will unlock the volume.

After the Windows operating system volume has been successfully unlocked, BitLocker uses encrypted information stored in the volume metadata and Windows registry to unlock any data volumes configured for automatic unlocking.

Event Details

Product: Windows Operating System
ID: 24600
Source: Microsoft-Windows-BitLocker-Driver
Version: 6.1
Message: The SRK was found to be invalid during restart.


Turn on the Trusted Platform Module

BitLocker entered recovery, and a user has successfully completed the recovery process by using a recovery key (stored on a USB flash drive) or a recovery password (entered manually at the recovery screen). The most recent recovery session, in which no Trusted Platform Module (TPM) could be found, can be caused by circumstances such as:

  • Using the TPM Management Console to turn off the TPM
  • BIOS configuration that "hides" the TPM from Windows
  • TPM or motherboard hardware failure or replacement
  • Moving the encrypted volume to a new computer that does not contain a TPM

If you turned off the TPM in the TPM Management Console or the BIOS, use the same tool to turn on the TPM. If the TPM or motherboard has been replaced, or you have moved the volume to a new computer, disable and re-enable BitLocker to use the new TPM.

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To disable and re-enable BitLocker:

  1. Click Start, and then click Control Panel.
  2. Click Security.
  3. Click BitLocker Drive Encryption.
  4. If the User Account Control dialog box appears, verify the proposed action is correct, and then click Continue.
  5. Click Turn off BitLocker.
  6. Click Disable BitLocker.
  7. In the BitLocker Drive Encryption window, click Turn On BitLocker.
  8. Close the BitLocker Drive Encryption window.


To verify that BitLocker has started successfully:

  1. If the computer is not running, start the computer.
  2. If BitLocker has been configured to use a USB flash drive, insert the USB flash drive. If BitLocker has been configured to use a PIN, enter your PIN when prompted.
  3. Verify that Windows Welcome Screen, Logon Screen or Desktop appears. This indicates that BitLocker has correctly unlocked the Windows operating system volume.
  4. Log on to Windows and access any data volumes that are encrypted with BitLocker.

Note: Data volumes can be configured to be automatically unlocked or to require manual unlocking.

BitLocker Startup

Core Security