The Microsoft outage caused by a CrowdStrike software update has caused the return of a familiar, if unwanted, screen for many Windows users: The so-called “blue screen of death,” indicating their computer systems aren’t functional. 

The outage has affected consumers as well as businesses across the globe in the airline, banking, media and healthcare industries. Blue screens of death were visible on computer screens at multiple airports Friday, according to images shared on social media. 

The blue screen of death has been around for decades, with the screen designed for early Windows systems to display when users’ operating systems glitched. Microsoft, which describes them as “blue screen errors” or STOP code errors, says the screen continues to be displayed “if a serious problem causes Windows to shut down or restart unexpectedly.”

The worldwide outage was caused by a technical problem that global cybersecurity firm CrowdStrike said it had identified in its software and was working to resolve. CrowdStrike provides antivirus software to Microsoft for its Windows devices.

In a tweet posted Friday morning, Microsoft said its “previously impacted Microsoft 365 apps and services have recovered.”

However, some customers responded that their computers were still displaying blue screens of death.

How can I fix the blue screen of death?

In an earlier social media post, Microsoft said that users can fix the blue screen of death by restoring their Windows 365 Cloud PC “to a known good state prior to the release of the update,” or replacing the buggy version of Windows 365 to the system right before CloudStrike issued its faulty update.

Microsoft included a link to a page with instructions on how to restore Windows. Users are given choices of various restart points that are between 4 hours to 24 hours earlier.

In a separate update on its website, Microsoft also said that users may encounter a bug check called BSOD, or blue screen of death, “and get stuck in a restarting state.”

In other words, the BSOD indicates that a computer has been knocked offline and that its operating system is not functional, sometimes forcing users into what can seem like a never-ending recovery loop before the PCs start properly again. 

How long does it take to get rid of the blue screen?

Microsoft warned that its customers may have to reboot as many as 15 times before they’re successful in restoring their computing systems. 

Microsoft said that some users have reported that they have been able to successfully reboot their machines. 

“We have received reports of successful recovery from some customers attempting multiple Virtual Machine restart operations on affected Virtual Machines,” the company said. It advises Windows users to login to the Azure Portal, its cloud computing product, and to initiate a restart.