Microsoft Releases Emergency Update to Tackle Windows 11 Boot Failure
Microsoft releases an out-of-band update to fix a boot failure issue caused by the May 2025 Patch Tuesday.
Key Takeaways:
- Microsoft issues an emergency update for Windows 11 (23H2 & 22H2) after a major installation failure.
- A critical system file error was causing boot issues, mainly in virtual machines.
- IT admins can now access the fix via the Microsoft Update Catalog.
Microsoft has rolled out an urgent out-of-band update (KB5062170) for Windows 11 versions 23H2 and 22H2, targeting a critical installation failure from the May 2025 Patch Tuesday. IT admins, especially those managing virtual environments, should prioritize this fix to prevent boot errors and system downtime caused by the corrupted ACPI.sys file.
What triggered the emergency update?
Last month, Microsoft confirmed it was investigating reports of serious issues caused by the security patch KB5058405 on some Windows 11 devices. After installing the update, affected PCs failed to boot and displayed error code 0xc0000098 during startup. The root cause was traced to a missing or corrupted ACPI.sys file, which is a critical system driver that helps Windows manage hardware resources and power functions.
“We are aware of an issue installing the May Windows security update (KB5058405) on some Windows 11, version 22H2 and 23H2 devices. Affected devices might encounter the following recovery error: Your PC/Device needs to be repaired. The operating system couldn’t be loaded because a required file is missing or contains errors. File: ACPI.sys. Error code: 0xc0000098,” Microsoft explained.
According to Microsoft, this issue primarily affected virtual machines, including Azure Virtual Machines, Azure Virtual Desktop, and on-premises virtual machines hosted on Citrix or Hyper-V. This means that it’s more likely a headache for enterprise customers rather than Windows 11 Home and Pro users.
How to download and install the update on Windows 11 PCs?
Microsoft says that customers can download the out-of-band update through the Microsoft Update Catalog. It also brings all the improvements and bug fixes included in the May 2025 Windows non-security preview update. Once installed, users will need to reboot their Windows 11 PCs.
Last month, Microsoft released an out-of-band update to address a bug that was previously causing Windows 10 PCs to get stuck on BitLocker recovery screens. This issue affected Windows 10 22H2 and Windows 10 Enterprise LTSC 2021.
Rabia has a master's degree in Software Engineering and she has years of experience writing professionally about Microsoft products and other technologies. Rabia has also written for OnMSFT.com as well as Windows Report. She is always up to date on t...
