The Windows 10 boot and shared data partitions somehow got encrypted with Bitlocker (and thus are inaccessible from the Win 8.1 install) after a repair shop swapped the motherboard.

If you have enabled encryption on Windows 10 build 10240 and then upgrade to build 10586, the encryption works fine. While there is no official word so far, an unofficial workaround is available.

Windows 10 22H2 has received its latest update today. The new release, Build 19045.3271 (KB5028244), brings a bunch of important bug fixes as well as improvements, including a BitLocker fix and more.

How to disable BitLocker on Windows 10. To remove the drive encryption, use these steps: Open Start. Search for Control Panel and click the top result to open the app. Click on System and Security.

On Windows 10, you may need to temporarily suspend BitLocker encryption to perform specific tasks, such as firmware, hardware, and Windows updates, using Control Panel, PowerShell, and Command ...