The company behind a major IT glitch says it's working on a fix.
The outage, linked with cyber security firm CrowdStrike, is affecting Windows users in multiple countries.
CrowdStrike has confirmed it is not a security incident or cyberattack.
In a statement, the firm said it has identified and isolated the issue, and "a fix has been deployed".
The company is working with customers affected by a defect found in a 'single content update' for Windows hosts. Mac and Linux hosts are not impacted.
Many Microsoft users reported being greeted by a "Blue Screen Of Death" on Friday morning as a result of the outage.
CEO of Smartech247 Cyber Security, Raluca Saceanu, explains what's likely to have gone wrong.
"They [CrowdStrike] have run an update and the computers and servers that are running these agents, they are stuck in a restart loop, so they cannot be accessed.
"And a lot of them are encrypted with BitLocker as well, which prevents the access further.
"So, unfortunately, this is going to be a nightmare for IT administrators because most of them will have to manually update and work on each machine one-by-one".
The outage early on Friday morning impacted airline passenger check-ins, bank payments, as well as some newsrooms and broadcasters.
However, the National Cyber Security Center says all essential services in Ireland are operating normally, with no government IT currently affected.
At Dublin Airport, Ryanair is advising passengers to arrive three hours ahead of their fights, as there are issues with check-ins and boarding passes.
Passenger advice:
Due to a global IT issue, Ryanair is experiencing challenges with its check-in processes this morning and have requested that their passengers arrive at the airport 3 hours prior to their flight.
The @DublinAirport team is on hand to assist Ryanair and… https://t.co/N6DDFRb1dU pic.twitter.com/Qj6dOAyi6I— Dublin Airport (@DublinAirport) July 19, 2024
