Microsoft probes Windows 11 boot failures after January

• Key Takeaways:
• Microsoft has opened an investigation after some Windows 11 machines failed to start following January security updates.
• Affected devices are reported to be unable to boot; Microsoft is working to identify root cause and provide fixes or rollbacks.
• Users should avoid forced reinstalls, try recovery options (Safe Mode, Startup Repair) and monitor official Microsoft channels for patches.

What happened

Microsoft is investigating reports that some Windows 11 systems fail to boot after installing January security updates. The issue has prompted a formal probe to determine why updates are preventing affected machines from starting normally.

Scope and impact

Details about how many devices are affected and which configurations are at highest risk remain limited. The problem appears linked to the January security rollup, and reports indicate it can leave systems unable to reach the Windows desktop.

Microsoft's response

Microsoft has opened an investigation and will provide guidance and fixes as it identifies the cause. Expect official advisories, support articles, and possibly update rollbacks or replacement patches as the company confirms a resolution.

What users should do now

If your Windows 11 PC fails to boot after recent updates, do not immediately perform a full reinstall. First try built-in recovery options: use Safe Mode, run Startup Repair, or access System Restore from the Windows Recovery Environment to remove recent updates.

On machines that still boot, pause automatic updates until Microsoft issues a confirmed fix. Back up important files and create a recovery drive if possible. Avoid installing unofficial workarounds that could cause data loss.

For IT admins

Enterprises and IT teams should temporarily block or defer the January security updates in managed environments until Microsoft publishes mitigation guidance. Validate backups and recovery plans and test updates on a small group before wide deployment.

Follow-up and where to watch

Monitor Microsoft’s official support channels, Windows health dashboards, and trusted tech news sources for verified instructions and patch releases. Microsoft is expected to update its guidance as the investigation progresses.

We will update this story when Microsoft releases details on affected builds, the root cause, and an official fix or workaround.