Answer

Windows provides a BitLocker option which can be enabled to protect the system data.

When hardware or firmware option changes are detected, the system could potentially lock up the system and require the user to enter the system BitLocker recovery key to unlock the system access.

 The BitLocker recovery key is a 48-digit string, looks like below format:

XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX-XXXXXX 

Find the BitLocker Recovery Key

If you have a Microsoft account logged in, the recovery key will be stored in the Microsoft account.

1. Open a web browser and visit the URL: https://aka.ms/myrecoverykey

2. Enter Microsoft Account & Password to log in the account.

3. Look for the device name that has been locked up and get the key ID

4. Enter the corresponding Recovery Key to unlock the system.

For other methods to find the BitLocker recovery key, refer to Find your BitLocker recovery key.

*Notice:

1. The BitLocker key will not be kept and cannot be bypassed in any condition except its owner. 

2. If the Recovery key is lost, the system must be wiped out and re-install.