Microsoft server outage: How a single failure triggered 'digital lockdown' across 74 countries

A major outage in Microsoft's server network disrupted businesses, offices and essential services across 74 countries, leaving millions of users unable to access emails, attend video meetings or retrieve files. The disruption lasted nearly 22 hours, exposing how heavily the global economy depends on Microsoft's digital infrastructure.

In today’s episode of DNA, Rahul Sinha, Managing Editor of Zee News, conducted a detailed analysis of the worldwide disruption, examining its impact on businesses and ordinary users, the estimated financial losses and the technical failure that brought several services to a standstill.

The outage first came to light in the United States, where users began reporting problems with Microsoft's email platform, Outlook. Screenshots showing error messages quickly appeared on social media. Soon, Microsoft Teams, the company's video-conferencing service, also faced problems, followed by disruptions to several other platforms.

The impact extended to more than a dozen Microsoft services. Outlook stopped working, Teams became inaccessible, users faced difficulties accessing the AI assistant Copilot, and OneDrive, the company's online storage platform, became unavailable. Microsoft Edge was also among the services users reported having trouble accessing.

Why Microsoft's Outage Had A Global Impact

The scale of the disruption becomes clearer when viewed against Microsoft's worldwide user base. According to the company's latest figures, Microsoft 365 has 450 million users, while Copilot has more than 30 million. Over 1.5 billion people use computers running the Windows operating system, and Microsoft Teams has more than 320 million active users.

The volume of activity across these platforms is equally significant. Outlook.com handles more than 35 million emails every minute. Microsoft Teams accounts for around 70 million hours of global video calls every day, while Copilot receives approximately 1.1 billion queries daily.

OneDrive, meanwhile, handles around 200,000 files, amounting to nearly 20,000 TB of data, every day. To put that figure into perspective, 20,000 TB is equivalent to around 4,000 films, each three hours long.

With so many individuals and organisations relying on these services, the outage had consequences far beyond office communication. Employees could neither send nor receive emails, attend online meetings or access files stored on OneDrive. The disruption affected users across countries rather than remaining confined to a particular office or region.

Indian Airlines Among Those Affected

India also witnessed the effects of the Microsoft outage, particularly in the aviation sector.

At Delhi airport, SpiceJet cancelled three flights, while two others were delayed. IndiGo's email support service was affected, and Akasa Air and Air India also experienced delays in their email-related services.

The disruption was not limited to India. Japan's IT industry was badly affected, with the government monitoring the situation. In Australia, businesses, government departments and several institutions reported problems. Some retailers struggled to process orders and bills received through email, while technical difficulties were also reported at schools.

Britain's National Health Service (NHS) was among the public institutions affected by the outage.

Some features of OpenAI and ChatGPT also stopped working, adding to the disruption beyond Microsoft's own platforms.

Estimated Losses From The Global Outage

The financial damage caused by the outage is yet to be officially calculated. However, estimates prepared by the DNA research team suggest that the losses could be substantial.

If 50 per cent of office work worldwide was affected by the disruption, the estimated loss in a single day could reach around Rs 5 lakh crore. These are provisional estimates, and the actual financial impact could be higher.

Microsoft has faced a major disruption of this kind before. On 19 July 2024, a faulty update caused Windows operating systems to crash, affecting around 8.5 million computers worldwide. The estimated financial loss from that incident was Rs 51,000 crore.

What Caused The Microsoft Server Outage?

The disruption was linked to an error during routine server health checks. Microsoft's servers regularly undergo these checks to establish whether they are functioning properly. However, a mistake in the process caused several servers that were working normally to be marked as failed.

Consequently, a large number of servers became unavailable. This increased the workload on the remaining operational servers, which then came under additional pressure and began failing as well.

The failures triggered a chain reaction, with one server problem leading to another. This eventually disrupted Microsoft's services across 74 countries.

Microsoft's Efforts To Restore Services

Microsoft began working on several measures to bring its services back online. The affected servers were being isolated to allow them to stabilise without additional pressure. The company was also restarting servers and checking their stability before gradually reconnecting them to the main network.

Rather than restoring all services simultaneously, Microsoft opted for a phased approach to bring its systems back online in a controlled manner.

The outage lasted nearly 22 hours, with some services beginning to return after 7:30 pm. In a subsequent statement, Microsoft said it had observed improvements across North America, most of Europe and the Asia-Pacific region. The company added that its focus remained on completing the restoration of its services.

The incident has raised serious questions about the world's dependence on a handful of major technology platforms. A failure within one company's server network was enough to disrupt offices, businesses, airlines and public services across continents, highlighting the risks of an increasingly interconnected digital economy.