Hi, @Ken Kirk
The update may have triggered the BitLocker recovery screen. Do not reset or reinstall Windows yet because this could erase your files.
On another device, sign in using the Microsoft account connected to the computer:
- BitLocker recovery keys https://account.microsoft.com/devices/recoverykey
- If you set up or used the device with a work or school account, you can also check here: https://aka.ms/aadrecoverykey
- Match the "Key ID" shown on the computer with the recovery key listed on the page, then enter the 48-digit key.
If you can enter the recovery key but Windows still does not start, please tell me what screen or error appears next.