Microsoft has confirmed that some Windows 11 users may experience boot failures after installing the January 2026 security update. The issue is likely to impact users running Windows 11 version 24H2 and 25H2 on physical machines. Microsoft is exploring potential fixes and workarounds, and users can manually recover their PC by entering the Windows Recovery Environment and uninstalling the latest security patch. This issue is the latest in a series of problems with the January 2026 Patch Tuesday updates.