Windows global IT outage: what we know so far

Businesses and institutions around the world have been knocked offline after an IT outage. In the UK, GP doctors’ surgeries have said they are unable to access patient records or book appointments. Sky News was off air for a few hours but resumed broadcasting, while Britain’s biggest rail company warned passengers to expect disruption because of “widespread IT issues”.

Around the world banks, supermarkets and other major institutions reported computer problems disrupting services, with some airlines warning of delays and others grounding flights. Here is what we know so far:

What has the Windows outage affected?

Companies including banks, telecommunications firms, TV and radio broadcasters and supermarkets around the globe all reported IT issues. Airlines were affected, too, with flights on US airlines including American Airlines, Delta and United Airlines being grounded. Airports in Germany and Spain were also reporting issues.

Automated boarding scanners at Edinburgh airport went offline, a witness from the Reuters news agency said. The airport was checking boarding passes manually, they said.

It is unclear whether operations were affected at Stansted, but many flights were displaying “please wait” announcements on the boards inside.

Amsterdam’s Schiphol airport said: “There is currently a global system failure. This disruption also has an impact on flights to and from Schiphol. The impact is now being mapped.”

Berlin’s Brandenburg airport said that “due to a technical fault, there will be delays in check-in”.

The emergency 911 lines in the US state of Alaska went down, according to the state troopers service. “Due to a nationwide technology related outage, many 911 and non-emergency call centres are not working correctly across the state of Alaska,” a statement read.

In the UK, rail services at Southern, Thameslink, Gatwick Express and Great Northern – all Govia Thameslink railway’s brands – were experiencing widespread IT issues.

The London Stock Exchange is among businesses affected. In a statement, it said: “RNS news service is currently experiencing a third-party global technical issue, preventing news from being published on www.londonstockexchange.com. Technical teams are working to restore the service. Other services across the group, including London Stock Exchange, continue to operate as normal.”

The NHS booking system used by doctors in England is also offline, medical officials said on X.

TV and radio broadcasters were affected, and SkyNews was not able to broadcast live TV on Friday morning. David Rhodes, the executive chair of the Sky News Group, said on X: “Sky News have not been able to broadcast live TV this morning, currently telling viewers that we apologise for the interruption. Much of our news report is still available online, and we are working hard to restore all services.

Turkish airlines, KLM, Eurowings, Swiss International Air Lines and Wizz Air said they were facing technical challenges, with longer check-in times and some flights delayed or cancelled.

Some flight screens at Sydney and other airports across Australia went blank on Friday evening, with Virgin Australia telling passengers to expect cancellations and delays.

Melbourne airport said in a post on X that Jetstar was “experiencing a significant outage” while Qantas and Virgin were “slowly processing passengers”. Jetstar’s international arm and the Singaporean carrier Scoot were also experiencing problems.

The Commonwealth Bank confirmed some PayID payment transactions were affected, while it is understood customers at ANZ were also having trouble with some transfers.

Where have businesses been affected?

Issues have been reported from across the globe, including in India, the US, Europe, the UK, Australia and New Zealand.

How widespread is the IT outage?

The cause of the outage is still being investigated but it appears to be affecting Windows PCs globally. The IT security firm CrowdStrike ran a recorded phone message on Friday saying it was aware of reports of crashes on Microsoft’s Windows operating system relating to its Falcon sensor.

CrowdStrike is a cybersecurity company, and Falcon sensor is software designed to prevent computer systems from cyber-attacks. Earlier this morning, the company warned its users that Windows systems were “experiencing a bug check/blue screen error related to the Falcon sensor,” and said that its engineering teams were working to fix the issue.

“Thanks for contacting CrowdStrike support. CrowdStrike is aware of reports of crashes on Windows … related to the Falcon sensor,” a prerecorded message said.

The president of CrowdStrike, George Kurtz, said the problem was caused by a “defect found in a single content update for Windows hosts”.

He wrote on X: “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”.

The UK’s Ministry of Defence said it was tracking the situation and was unaffected. It said it was not aware of any hostile actor involvement.

The UK’s science, innovation and technology secretary, Peter Kyle, said government departments “are working seamlessly together to understand the nature of today’s outages and respond appropriately and swiftly”.

Separately, other UK government officials are indicating they are not treating this as a cyber-attack from hostile states or criminals.