• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
TechOutage

Major Microsoft and Crowdstrike disruptions ground planes, banks, McDonald’s stores and the London Stock Exchange

By
Amy Thomson
Amy Thomson
,
Shona Ghosh
Shona Ghosh
,
Vlad Savov
Vlad Savov
, and
Bloomberg
Bloomberg
Down Arrow Button Icon
By
Amy Thomson
Amy Thomson
,
Shona Ghosh
Shona Ghosh
,
Vlad Savov
Vlad Savov
, and
Bloomberg
Bloomberg
Down Arrow Button Icon
July 19, 2024, 4:23 AM ET
Updated July 19, 2024, 8:16 AM ET
United Airlines was among the major companies to disclose a variety of issues with communications to customer service.
United Airlines was among the major companies to disclose a variety of issues with communications to customer service. Beata Zawrzel—NurPhoto via Getty Images

Computer systems at businesses and public services around the globe were disrupted after a botched update of a widely used cybersecurity program took down Microsoft Corp. systems. 

Recommended Video

CrowdStrike Holdings Inc. Chief Executive Officer George Kurtz posted on X on Friday that the fault had been identified and “a fix has been deployed,” adding that it wasn’t a cyberattack. Compounding the issue, Microsoft also reported an apparently unrelated problem with its Azure cloud service. 

Hitting airlines, banks and healthcare systems, there have been few outages of this scale. The cascading failures underscore vulnerabilities of the modern economy and the central role of security software, which has deep access to operating systems.

“This is unprecedented,” Alan Woodward, professor of cybersecurity at Surrey University, told Bloomberg News. “The economic impact is going to be huge.”

CrowdStrike is actively working with customers impacted by a defect found in a single content update for Windows hosts. Mac and Linux hosts are not impacted. This is not a security incident or cyberattack. The issue has been identified, isolated and a fix has been deployed. We…

— George Kurtz (@George_Kurtz) July 19, 2024

The scale of the disruption reflects the enduring ubiquity of Microsoft’s Windows, and the sizeable adoption of CrowdStrike’s security software. Windows is installed on more than 70% of machines, according to StatCounter, and CrowdStrike is the global leader in modern corporate protection software, according to estimates by research firm IDC.

Although its software is designed to thwart threats, CrowdStrike customers posted blue error screens to social media as they were prevented from accessing laptops and corporate computers. 

McDonald’s Corp., United Airlines Holdings Inc., and the LSE Group were among the major companies to disclose issues from communications to customer service. Airports from Singapore to Zurich were impacted. The New York subway said arrival information is unavailable for most of its lines, but services are operating. Bloomberg terminals were operating as normal.

Microsoft said it was “aware of an issue affecting Windows devices due to an update from a third-party software platform.” The company said it fixed a separate glitch affecting Microsoft 365 apps. 

The outages weighed on several sectors, including airlines, insurers and stock exchange operators. Shares in CrowdStrike sank 20%, while Microsoft fell 2.9%.

Past disruptions have been less severe. In 2017, a series of errors within Amazon.com Inc.’s cloud service affected the operation of tens of thousands of websites. In 2021, issues at content delivery network Fastly took out several media networks including Bloomberg News and there were separate disruptions at Amazon’s AWS cloud service.

“I don’t think it’s too early to call it: this will be the largest IT outage in history,” Troy Hunt, an Australian security consultant and creator of the hack-checking website Have I Been Pwned, said in a post on social media platform X.

The first glitches emerged in the US late on Thursday and were blamed on the failure of Microsoft services Azure and 365, the company’s internet-based office software suite. 

Problems linked to CrowdStrike then surfaced hours later in Asia and rippled across systems in Europe. As the US commute got underway, the New York subway said arrival information was unavailable but trains and buses were still running.

Join us at the Fortune Workplace Innovation Summit May 19–20, 2026, in Atlanta. The next era of workplace innovation is here—and the old playbook is being rewritten. At this exclusive, high-energy event, the world’s most innovative leaders will convene to explore how AI, humanity, and strategy converge to redefine, again, the future of work. Register now.
About the Authors
By Amy Thomson
See full bioRight Arrow Button Icon
By Shona Ghosh
See full bioRight Arrow Button Icon
By Vlad Savov
See full bioRight Arrow Button Icon
By Bloomberg
See full bioRight Arrow Button Icon

Latest in Tech

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • World's Most Admired Companies
  • See All Rankings
  • Lists Calendar
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Tech

dario
CommentaryAnthropic
Anthropic’s most powerful AI model just exposed a crisis in corporate governance. Here’s the framework every CEO needs.
By Jeffrey Sonnenfeld, Stephen Henriques, Dan Kent and Holden LeeMay 2, 2026
2 hours ago
Photo of vegan cheese products
AITech
A Mark Cuban–backed vegan cheese company trained AI to scrutinize cardboard boxes. It’s saved $400,000
By Jake AngeloMay 1, 2026
21 hours ago
Young trade worker learning on job
SuccessHiring
Forget Big Tech: Small businesses will hire nearly 1 million grads in 2026—and some of the hottest roles are gloriously AI-proof
By Emma BurleighMay 1, 2026
22 hours ago
Andrew McAfee
SuccessCareers
MIT AI expert warns automating Gen Z entry-level jobs could backfire—and cost companies their future workforce
By Preston ForeMay 1, 2026
23 hours ago
duke
Big TechAmazon
Amazon Prime Video reaches deal with Duke Blue Devils to air 3 games per season
By The Associated PressMay 1, 2026
1 day ago
valerie
CommentaryLayoffs
Tesla’s former HR chief: the AI layoff panic Is built on a false premise—here’s what most workers need to know
By Valerie Capers WorkmanMay 1, 2026
1 day ago

Most Popular

Scott Bessent on financial literacy: 'it drives me crazy' to see young men in blue-collar construction jobs playing the lottery
Personal Finance
Scott Bessent on financial literacy: 'it drives me crazy' to see young men in blue-collar construction jobs playing the lottery
By Fatima Hussein and The Associated PressMay 1, 2026
1 day ago
China dominates the world's lithium supply. The U.S. just found 328 years' worth in its own backyard
North America
China dominates the world's lithium supply. The U.S. just found 328 years' worth in its own backyard
By Jake AngeloApril 30, 2026
2 days ago
The U.S. economy is booming — just not where 50 million Americans live
Commentary
The U.S. economy is booming — just not where 50 million Americans live
By Derek KilmerMay 1, 2026
1 day ago
Current price of oil as of May 1, 2026
Personal Finance
Current price of oil as of May 1, 2026
By Joseph HostetlerMay 1, 2026
1 day ago
A Chick-fil-A worker got fired and then showed up behind the register to allegedly refund himself over $80,000 in mac and cheese
Law
A Chick-fil-A worker got fired and then showed up behind the register to allegedly refund himself over $80,000 in mac and cheese
By Catherina GioinoMay 1, 2026
21 hours ago
Apple cofounder Ronald Wayne—whose stake would be worth up to $400 billion had he not sold it in 1976—says that at 91, he has no regrets
Success
Apple cofounder Ronald Wayne—whose stake would be worth up to $400 billion had he not sold it in 1976—says that at 91, he has no regrets
By Preston ForeApril 27, 2026
5 days ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.