A global Microsoft outage early Friday morning, triggered by an update from cybersecurity firm Crowdstrike, left numerous Windows PCs stuck in the “blue screen of death” (BSoD) and disrupted various services.
The problems began Thursday evening, with users reporting issues with Microsoft, its store, and Microsoft 365 services around 6:30 p.m. ET. Microsoft acknowledged the disruptions by 7:40 p.m. ET, working overnight to reroute traffic and mitigate the issue.
The root cause was identified in Microsoft Azure’s cloud service, particularly affecting Virtual Machines running Windows Client and Server with the CrowdStrike Falcon agent. This resulted in machines entering a continuous restart loop.
Crowdstrike quickly retracted the faulty update, confirming that no Mac or Linux systems were affected. CEO George Kurtz assured users on X that the issue was isolated and a fix was being deployed, emphasizing that this was not a security incident or cyberattack.
Despite the rollback, Azure’s problems impacted Microsoft 365 services, including Microsoft Defender, OneNote, OneDrive, and Teams. Most services have since been restored, though issues with Teams persist.
The outage’s repercussions were significant, grounding flights globally. Airlines like Southwest, Frontier, American Airlines, Delta, and United experienced system failures, leading to approximately 1,400 flight cancellations. The FAA monitored the situation, assisting with ground stops as necessary.
By 6:45 a.m. ET Friday, Microsoft advised users of Windows 365 Cloud PCs to restore their machines to a previous state to resolve lingering issues. Microsoft and Crowdstrike continue to work on further mitigations.
