When encrypting your device using BitLocker, you be asked how you wish to back up your recovery key.
Using Save to your Microsoft account
- Select the "Save to your Microsoft account" option seen on the BitLocker Drive Encryption screen.
- If your device is not connected to your personal Microsoft account, you will receive this message. (NOTE: If you don't have a personal Microsoft account, please create one).
- In this situation, however, it is not necessary to switch to a Microsoft account. Rather, it is sufficient to link your device with your Microsoft account. To do so, add it in the Settings under Accounts > Email and accounts.
- After this, you can save your BitLocker recovery key to your Microsoft account.
Read the BitLocker key from the Microsoft account
If you need the recovery key, you can log on to your Microsoft account on any device and read all the keys for the computers that you have stored there. To do so, visit https://account.microsoft.com/devices/recoverykey. After signing in with the Microsoft account you used, a list with the keys appears. You can also delete them from here, if necessary.