On Windows 11, Microsoft has confirmed that the January 2026 Security Update (KB5074109, build 26200.7623) is triggering additional issues that can prevent some devices from booting properly.
Although the company has already released two out-of-band updates to address earlier problems, Microsoft now acknowledges that this particular failure remains unresolved, and neither emergency patch (KB5077744 and KB5078127) corrects the boot issue.
