Microslop suspects some PCs might not boot after Windows 11 January 2026 Update (KB5074109)

Microsoft is aware of an issue causing some PCs to fail to boot after installing the Windows 11 January 2026 Update (KB5074109). The issue affects specific PCs, leading to a Black Screen of Death error with stop code UNMOUNTABLE_BOOT_VOLUME. Microsoft is investigating the cause and has released an emergency update (KB5078127) to address the problem. Other issues caused by the update include Outlook Classic freezing, third-party apps becoming unresponsive, and sleep mode not working on older PCs.