Microsoft released its Windows 10 on Wednesday describing it as the "best Windows ever." One of its key features is Windows Hello, making the latest upgrade the most secure version.

Microsoft first introduced Windows Hello in March as part of the company's effort to make Windows 10 more personal and more secure. It allows users to log in or unlock devices with their faces or fingers through biometric authentication, instead of the traditional passwords or PINs that are vulnerable to hackers.

"We want your devices to recognize you, to understand what you're saying... we want the experience to go wherever you do and we want you to feel a great sense of TRUST as you go," Joe Belfiore, Microsoft Vice President for Operating Systems Group, wrote in a blog post.

One can setup Windows Hello by going into their Settings, enabling PIN, and letting the camera detect his or her face. Microsoft has integrated 3-D depth-sensing and RealSense camera in the feature so wearing glasses or being in the dark would not be an issue, your device would still recognize you.

"It's actually using different dark and light shadows on the contours of my face," Chaitanya Sareen, Microsoft's principal program director on Windows, said to Time. "If it was pitch dark it would still sign me in."

Windows Hello is designed to protect devices from cyber attacks which is a known concern in today's technology.

"It's a solution that government, defense, financial, health care and other related organizations will use to enhance their overall security, with a simple experience designed to delight," Belfiore told CNET. "There is no shared password stored on [Microsoft's] servers for a hacker to potentially compromise."

Microsoft has partnered with Lenovo, HP, Dell and Acer in pre-loading their latest devices with Windows 10 features including Windows Hello. The upgrade is available for free download in 190 countries and is compatible with PCs or tablets running on Windows 7 or Windows 8.1.