Windows 11 security update leaves virtual machines unable to boot

Facepalm: A recent Windows 11 security update has left some users facing unexpected trouble: their computers refuse to boot. The update in question, KB5058405, was automatically rolled out to devices running Windows 11 versions 23H2 and 22H2. Instead of simply improving security, it has triggered a critical error for a subset of users. The problem arises after installation, when affected PCs halt during startup and display a recovery error with the code 0xc0000098. This message typically indicates that a required file – often ACPI.sys, a crucial system driver responsible for managing hardware resources and power states – is missing or corrupted. Some users have reported seeing the same error code referencing other system files, suggesting the issue may not be limited to ACPI.sys alone. Microsoft has acknowledged the problem, stating that it primarily impacts devices running in virtual environments. The most vulnerable systems include virtual machines hosted on Azure Virtual Machines, ... Read full article.