An update by the cyber-security company CrowdStrike to its software Falcon on Friday disabled about 8.5 million computers worldwide, including in India, running the Windows operating system, disrupting airline operations, stock markets activities, some media broadcast operations and payment gateways.

Experts have called it the largest IT outage of all time.

The update to CrowdStrike Falcon led to the ‘blue screen of death’ (when the screen turns blue and the computer stops operating) for Windows systems worldwide and hobbled much of what the modern world depends on, from air travel to health care to banking and beyond.

It was the US company CrowdStrike itself which owned up to the mistake, stating in an update late Friday evening that a “logic error” (a kind of programming error), triggered by a sensor configuration update to its cyber-security software Falcon, was the culprit.

It said it was “deeply sorry for the inconvenience and disruption” and that its “team is fully mobilised to ensure the security and stability of CrowdStrike customers”.

Microsoft said in a statement om Saturday that its estimates say the “update affected 8.5 million Windows devices”, which, though, the company continued in the same sentence, represents “less than 1 percent of all Windows machines”.

But “[w]hile the percentage was small, the broad economic and societal impacts reflect the use of CrowdStrike by enterprises that run many critical services,” the statement further said.

The software giant was keen to emphasise that the incident highlights how important it is for companies such as CrowdStrike to use quality control checks on updates before sending them out.

“It’s also a reminder of how important it is for all of us across the tech ecosystem to prioritize operating with safe deployment and disaster recovery using the mechanisms that exist.”