KB5040442 / KB5040427: Microsoft confirms Windows PCs boot into BitLocker recovery

A bug Windows 11 Patch Tuesday

Microsoft, on the second Tuesday of this month, released July 2024 Patch Tuesday updates for Windows 10 (KB5040427 / KB5040430 / KB5040434 / KB5040448), Windows 11 21H2/ 22H2 / 23H2 (KB5040442 / KB5040431) and Windows 11 24H2 (KB5040435).

Alongside security fixes, these Patches often introduce major bugs. With the July Update Tuesday, Microsoft has now confirmed that several versions of Windows, both client (Windows 10 /11) and Server, are affected by a BitLocker-related bug wherein a user PC will be stuck at a BitLocker recovery screen when booting up the system post installation of the Patch Tuesday update.

On its Windows health dashboard, describing the problem, Microsoft writes:

After installing the July 2024 Windows security update, released July 9, 2024 (KB5040442 / KB5040427), you might see a BitLocker recovery screen upon booting your device. This screen does not commonly appear after a Windows update. You are more likely to face this issue if you have the Device Encryption option enabled in Settings under Privacy & Security -> Device encryption. Resulting from this issue, you might be prompted to enter the recovery key from your Microsoft account to unlock your drive.

Affected platforms:

Client: Windows 11 version 23H2, Windows 11 version 22H2, Windows 11 version 21H2, Windows 10 version 22H2, Windows 10 version 21H2.

Server: Windows Server 2022, Windows Server 2019, Windows Server 2016, Windows Server 2012 R2, Windows Server 2012, Windows Server 2008 R2, Windows Server 2008.

Microsoft has also provided a workaround describing how users on affected PCs can work their way around the issue, and it requires the BitLocker recover key:

Workaround:

Your device should proceed to start up normally from the BitLocker recovery screen once the recovery key has been entered. You can retrieve the recovery key by logging into the BitLocker recovery screen portal with your Microsoft account. Detailed steps for finding the recovery key are listed here: Finding your BitLocker recovery key in Windows.

Next steps: We are investigating the issue and will provide an update when more information is available.

You can learn more about the bug here on the Windows health dashboard page on Microsoft's official website.