Microsoft investigates nasty Windows 11 bug that leaves PCs unable to boot – here’s what you need to know

• Windows 11 22H2 and 23H2 have been hit by a bug that can leave a PC unable to boot
• Microsoft is investigating this recovery error glitch in the May update
• Windows 11 Home users are unlikely to be affected, we’re told, but that doesn’t mean they can’t run into this showstopping affair

Those who haven’t yet installed the latest cumulative update for Windows 11 in May – by which I mean the upgrade released the week before last, not the most recent optional update – should be aware of a nasty bug that some users are encountering.

Microsoft has said that it’s investigating whether the May update can cause a showstopping error, which means your PC won’t boot. However, this warning is delivered with a welcome caveat that it isn’t likely to affect Windows 11 Home users. Still, that possibility isn’t ruled out, and given the gravity of the bug, it’s worth bearing in mind if you’re about to pull the trigger on this cumulative update.

Bleeping Computer reports that Microsoft has updated its release health dashboard with information on the bug, and how the upgrade might fall over with a ‘recovery error 0xc0000098 in ACPI.sys’ message.

This is no simple error or installation failure, though, because it leaves Windows 11 unable to boot and requires a repair to be run on the system. And whether that repair will be successful is anyone’s guess, as sometimes, these are the kind of situations that are tricky to recover from – and the OS won’t necessarily pull itself out of the hole that’s been dug.

The good news is that affected devices running Windows 11 22H2 and 23H2 – note that 24H2 is not affected here – are few in number. Primarily, this problem pertains to virtual machines, not physical Windows 11 PCs.

Microsoft explains: “Home users of Windows using Home or Pro editions are unlikely to face this issue, as virtual machines are mostly used in IT environments.”

However, being ‘unlikely’ does not equate to being impossible, and so there must have been some reports of Windows 11 PCs (as opposed to virtual machines) being affected by this unfortunate issue.

I did find one such recent report on Reddit, although it isn’t explicitly linked to the latest update being installed, so take that with a grain of salt. The error message was slightly different as well, but in its warning, Microsoft acknowledges that a file name other than ACPI.sys might appear in the error.

Analysis: A cautious approach may be wise here

Microsoft wouldn’t announce such an investigation lightly, so if you haven’t yet installed the May update, I think that it’s worth considering delaying the installation of that upgrade for a little longer. Mainly to allow for Microsoft to complete its investigation here, after all, you’ve waited a couple of weeks (for whatever reason) now, so what’s another week, or perhaps a bit longer?

It is possible to pause OS updates for over a month, even on Windows 11 Home, though you’ll be forced to apply any given patch after 35 days of deferring it.

In this additional time, you can wait for Microsoft to complete its deeper dive into what’s going on here, and hopefully that’ll lead to a fix being implemented soon, too.

Granted, you’d probably be very unlucky to encounter this recovery error, but even a small chance is off-putting, given that it could be a potentially thorny problem to extricate yourself from. Ultimately, the choice is yours, and if you’ve already installed the May update without encountering any such error, I should make it clear that you've got nothing to worry about.

Microsoft isn’t having a great time of things lately when it comes to bugs of a seriously unpleasant nature, as there was a real sting in the tail for some Windows 10 users with the May update, too.

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