A couple of days ago, Microsoft released the latest non-security update for Windows 11 and Windows 10. The latter received a bunch of useful fixes, while Windows 11 got some new features and changes. If you are tempted to try KB5039302, beware of a nasty bug that can seriously break your computer to the point of being completely unable to use it. Microsoft has just confirmed that KB5039302 is causing infinite restarts on some systems.
According to a post on the official Windows Health Dashboard website, the problem affects computers powered by client versions of Windows 11 22H2 and 23H2. It is most likely to happen if you use virtual machines and nested virtualization with software like CloudPC, DevBox, or Azure Virtual Desktop.
As there are no workarounds, Microsoft paused the rollout of KB5039302 to prevent the further spread of this quite severe bug.
After installing updates released June 26, 2024 (KB5039302), some devices might fail to start. Affected systems might restart repeatedly and require recovery operations in order to restore normal use.
This issue is more likely to affect devices utilizing virtual machines tools and nested virtualization features, such as CloudPC, DevBox, Azure Virtual Desktop. We are investigating to determine the precise conditions under which this issue can trigger.
While our investigation is underway, we are pausing the offering of this update via Windows Update and Windows Update for Business. For this reason, this update may not be presently offered to your device.
Microsoft says that Windows 11 Home edition users are less likely to encounter the bug since "virtualization is less common in home environments." But if you do use virtual machines on your Home device, you better stay away from KB5039302 and wait for Microsoft to deploy a fix.
Microsoft is working on a resolution and will provide more information soon.