(Reuters) - More than 97% of Windows sensors are back online, CrowdStrike's ( CRWD ) CEO George Kurtz said on Thursday, nearly a week after a software update by the cybersecurity firm triggered a global outage.

The company's Falcon platform sensor is a security agent installed on devices such as laptops and desktops that protects them from threats.

The outage happened because the advanced platform contained a fault that forced computers running Microsoft's ( MSFT ) Windows operating system to crash and show the so-called blue screen of death.

Microsoft ( MSFT ) said on Saturday about 8.5 million Windows devices had been affected in the outage that had left flights grounded, forced broadcasters off air and left customers without access to services such as healthcare or banking."Our recovery efforts have been enhanced thanks to the development of automatic recovery techniques and by mobilizing all our resources to support our customers," Kurtz said in a post on LinkedIn.