The boss of the cybersecurity firm responsible for worldwide IT outages admits it could be "some time" before all systems are back up and running
While the software bug has been fixed, experts say the manual reboot of each affected Microsoft computer will take a huge amount of work
Thousands of flights have been cancelled, with banking, healthcare and payment systems all affected
In the UK, GPs have been struggling to access records, pharmacies have been hit and TV channels knocked off air
The boss of cybersecurity firm Crowdstrike apologises for the disruption caused by its software update in an interview with US broadcaster NBC News.
"We're deeply sorry for the impact that we've caused to customers, to travellers, to anyone affected by this, including our companies," George Kurtz says.
We'll bring you more on this shortly.
Imran Rahman-Jones
Technology reporter
The website Downdetector tracks which sites maybe having tech issues - as you can see from the picture below, there was a large spike in reports of problems this morning in the UK:
But the drop-off from that spike shows that very few people are now reporting issues with many services – of course, that’s just a snapshot of some of the companies which seem to be affected.
But numbers now seem to be falling from their peaks a couple of hours ago.
Downdetector relies on people self-reporting problems, so it could just be that people aren’t sending in as many reports.
But the general trend seems to be that services are starting to get back up and running, though the real-world fallout of this will continue for days or even weeks.
Top UK officials met for an emergency Cobra meeting a little earlier, as No 10 says it isn't aware of the outage affecting government business.
Prime Minister Keir Starmer didn't chair the Cobra meeting, as he was holding cabinet with Ukrainian President Volodymyr Zelensky at Downing Street.
A No 10 spokeswoman says ministers are being regularly updated on the outage, and government is "working closely with the respective sectors and industries on this issue".
Hannah Gelbart
BBC What in the World podcast
I’m at Gatwick Airport in London, waiting to board a flight to Sicily.
There are loads of delays, so even though our airline says their systems are not affected by the IT outage it seems like we might be here for a while.
Lots of the people I’m meeting are coming from other places – and we’re all sharing photos of the queues at our airports in our group chat and playing bingo to see who is stranded closest to where we’re going.
Many passengers with flights to, from or within the UK have rights when delays occur.
What counts as a delay depends on the flight length but under certain conditions, passengers may be entitled to vouchers for food and drink, accommodation and transport, and could even be due compensation.
Passengers stuck in queues at Edinburgh airport say everyone is staying calm as they wait on news about their flights.
The airport is no longer accepting incoming flights that haven’t already taken off. Passengers whose flights have been cancelled are being asked to leave.
Microsoft says the "underlying cause" of the mass IT outage has been fixed for its apps, but "residual impact" is continuing to affect some services.
The company previously said the issue was due to "an update from a third-party software platform" - which has now been confirmed as Crowdstrike.
We've just brought you two posts from our experts on the nature and scale of the worldwide IT outage.
But on X, Tesla and X boss Elon Musk has tried to sum it up more succinctly.
"Biggest IT fail ever," he says.
Image source, Reuters
Joe Tidy
Cyber correspondent
Cyber-security experts are warning that, although there is now a software fix, it’s going to take a huge amount of work to get computers back up and running.
Crowdstrike’s bad software causes systems to "blue screen" and crash, which means they can’t restart to get the good update on to computers.
Researcher Kevin Beaumont says: "As systems no longer start, impacted systems will need to be started in ‘Safe Mode’, to remove the faulty update.
"This is incredibly time-consuming and will take organisations days to do at scale. Essentially we have one of the world’s highest impact IT incidents caused by a cyber-security vendor."
Liv McMahon
Technology reporter
Image source, ReutersBlue screens at checkouts in Sydney, Australia
PC users will know there are a whole host of error messages that can cause panic and frustration.
But those of us who have been met with Windows’ so-called blue screen of death (BSoD) before will feel the pain of those people worldwide seeing it appear today.
It’s what pops up when there is a critical error affecting the operation of your PC – in this case accompanied by an unending loop of trying and failing to restart and launch properly.
A BSoD can be prompted by hardware or software issues, but as Joe Tidy said in an earlier post, it's not the easiest thing to resolve – and can be less easy when dealing with fiddly software bugs.
Even though Crowdstrike says it has identified and fixed the erroneous update bricking Windows devices - those with devices caught in the loop will still need to take their own actions.
Victoria Craig
Reporting from Ankara
Image source, EPATurkish Airlines is one of the world's biggest (file picture)
Turkish Airlines, Turkey’s flag carrier, has confirmed it is affected by the massive global IT outage on Friday.
A spokesperson tells the BBC that as of 13:00 local time (11:00 BST), 84 of its flights to and from Istanbul, and various locations across Europe, have been cancelled.
Turkish Airline’s low-cost carrier, AJet, also says it is experiencing disruptions to online ticketing, reservations, and call centres.
Turkish Airlines apologised for the inconvenience and says flights will "gradually return to normal".
Jonathan Josephs
Business reporter
Further to those cancellation numbers, here's a new statement from Delta Airlines - the world's second biggest by passenger numbers.
"All Delta flights are paused as we work through a vendor technology issue.
"Any customers whose flights are impacted will be notified by Delta via the Fly Delta app and text message.
"Customers should use the Fly Delta app for updates. We apologize for the inconvenience as our teams work through this issue. Reports indicated that other airlines may also be impacted."
There were around 110,000 commercial flights scheduled across the world today - as of 11:00 BST, 1,390 have been cancelled, according to aviation analytics company Cirium.
Here's a national breakdown - we hope to have up-to-date UK figures soon:
Image source, ReutersBilbao airport in Spain earlier today
Joshua Nevett
Reporting from Luton airport
After the earlier delay to my 08:00 take-off, I’m pleased to say check-in is now open for my Wizz Air flight to Vilnius from Luton.
But it’s a slow process as passengers are being checked in manually. Clearly, the airline’s IT systems are still not functioning.
As I passed through the gate, my name was ticked off a list. Paper and pens in the age of AI.
It’s a stark reminder of how much we take basic IT systems for granted these days.
Joe Tidy
Cyber correspondent
It might seem extreme that a piece of cyber-security software can cause such a huge amount of damage - but these products are, by their nature, deeply ingrained in the innards of a computer network.
They have "god-like" access to all the inner workings of an IT system for obvious reasons.
These "End Point Protection" programmes have to be able to monitor the inner workings of computers to search for abnormalities that might be malicious software, or hackers poking around inside databases.
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Image source, Getty ImagesEarlier, the Metro service in the US capital, Washington DC, told users to expect delays because of the IT problems.
It now says, external "all Metrorail stations opened on time and service is running as scheduled".
UK cabinet minister Pat McFadden says he is in "close contact" with teams coordinating a response through Cobra - a committee which handles matters of national emergency.
McFadden adds ministers are working with their sectors and industries on the issue, in a statement published on X., external
Image source, Angus WalkerThe scene at Budapest airport earlier today
American Airlines says it has been able to "safely re-establish" its operation following a "technical issue with a vendor".
The US airline says its systems were back up and running by 05:00 ET (10:00 BST).
"We apologise to our customers for the inconvenience,” it adds.
As a reminder, the airline - along with many others - stopped flights taking off earlier today, as the IT chaos swept across the world.