Surface laptop, Red block, unlocked padlock

If your Surface Book is displaying a black screen with a red block and an unlocked padlock, it may be indicating that the device is prompting for a BitLocker recovery key. This can happen after certain updates or changes to the firmware. Here are some steps you can take:

1. Check for the BitLocker Recovery Key: If you have enabled BitLocker on your device, you will need to enter the recovery key. This key can often be found in your Microsoft account under the Devices section or may have been printed or saved elsewhere when you set up BitLocker.
2. Try the Volume + Power Button: Holding down the Volume-Up button while pressing the Power button is a common method to access recovery options. However, if this does not work, you may need to try other recovery methods.
3. Create a Recovery USB: If you are unable to access your device, creating a recovery USB can help. Since you mentioned issues with the serial number, ensure that you are entering the correct serial number for your specific Surface Book model. You can find the serial number on the device itself or in your Microsoft account.
4. Use the Surface IT Toolkit: If you have access to another computer, you can download the Surface IT Toolkit to create a recovery USB. Follow the instructions in the toolkit to select your device and create the recovery media.
5. Contact Microsoft Support: If you continue to have difficulties, contacting Microsoft Support may provide additional assistance tailored to your specific situation.

These steps should help you troubleshoot the issue with your Surface Book.

References:

• Prompted for BitLocker recovery key after installing updates to Surface UEFI or TPM firmware on Surface device
• Restore Surface device

The AI paragraph 3 suggests I check that I use correct serial number, I have checked it is correct over and over, unless the number printed under the Microsoft logo under the keyboard section is not the serial number, there is no other on it.