This is the resolution for the computer which is impacted after the Windows update 19H2.
What will happen if Windows update is carried out without taking appropriate precaution by SEM for the encrypted volumes.
When the Windows update (19H2) is deployed on any BIOS-based computer using MBR, the computer may hang. Following things may occur while performing such update without any precautionary measures:
1. When the update starts, computer will ask for update restart and SEM pre-boot will be prompt.
2. In the process, the 1st restart will trigger at 30 % of upgrade completion.
3. Again computer pre-boots and completes the upgrade upto 75 %.
4. Again the computer restarts and displays the pre-boot prompt for the password.
5. After receiving the correct password, BSOD ( UNMOUNTABLE BOOT VOLUME ) is visible. Then the computer goes into recovery mode.
Action on infected machine
At the time of Windows update, the computer goes into recovery mode. You can perform following actions to recover your computer.
1. If the computer goes into recovery mode, use rescue ISO (Win PE) and decrypt both, the boot and System Volumes.
2. Restart the computer and complete the Upgrade.
3. If encryption policy is applied, then allow the computer to encrypt again.