Microsoft has said it is "deeply sorry" for the service outage to its products, including Outlook and Teams, which has caused disruption around the world.
Services were broadly recovering by Friday afternoon, nearly 24 hours after issues first began, as Microsoft said it was making "encouraging progress" and email queues were nearing normal levels.
The outage hit more than 70 countries, disrupting everything from business operations to government services and personal users. More than 430 million people use the affected products worldwide.
Microsoft said the problem was a technical issue introduced during a "network capacity upgrade" and not related to cyber or artificial intelligence agents.
Experts said the event was a "stark reminder" of how heavily businesses and vital services rely on a small group of big tech providers.
Users began reporting they were having trouble accessing Microsoft 365 products on Thursday.
By Friday, the far-reaching issue was affecting institutions from the Japanese government and the Philippines Supreme Court to the Australian spy agency, and trains, hospitals and courts in North America.
Why is Microsoft's outage lasting so long and will emails be lost?
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In the UK, some parts of the NHS, including GPs and hospitals, were affected, as were some schools and police forces.
