Hi ChrisFountain,
Thank you for reaching Microsoft Community. I'm sorry to hear that you are unable to log in to your Surface Book due to the PIN issue.
To troubleshoot, please try first doing a Force Shutdown on the device by following the steps below: (reference: Force a shutdown and restart your Surface (microsoft.com))
- Press and hold the power button on your Surface until the screen turns off (about 30 seconds), then release it.
- Press and hold the volume-up button and the power button at the same time until the screen turns off (about 15 seconds), then release both.
The screen may flash the Surface logo, but continue holding the buttons down for at least 15 seconds. 3. After you release the buttons, wait 10 seconds. 4. Press and release the power button to turn your Surface back on. You should see the Surface logo.
After performing a Force Shutdown, try to log in on the device again. It the issue persist, please try to check if the device connected to your network by selecting the Wi-Fi icon on the lower-right area of the log in screen. Connect if not then restart the Surface. If it is already connected, try disconnecting it from the network then restart the Surface and try logging again using password if in case facial recognition still does not work.
If in case the issue persist after the steps provided, I suggest that we perform a reset on the device. We can try doing a reset first selecting the Keep my files option to save the files that you have on the device. To do this, press and hold the Shift key on the keyboard then tap the Power icon on the screen and select Restart. Release the Shift key once you have the Choose an option screen. Select Troubleshoot > Reset this PC and select Keep my files then follow the on-screen instructions.
Kind regards,
Marrion