The US Department of Defense (DoD) has agreed to upgrade more than four million of its devices to Windows 10 by January next year, with the platform's biometric authentication cited as an important factor.According to the Office of the DoD CIO, the Secretary of Defense has directed all U.S. DoD agencies to begin the rapid deployment of the Microsoft Windows 10 throughout their respective organizations for information systems currently utilizing Microsoft Operating Systems.From laptops to desktops to mobile devices, including Surface devices, the DoD is targeting its Windows 10 upgrade for completion in a year.In a Windows statement, the software firm noted that with Windows 10, that agencies can identify individuals and restrict access through integrated multi-factor authentication using biometric mechanisms like facial recognition or fingerprints using the Windows Hello and Windows Passport features.”It is exciting to see adoption of Windows 10 by so many enterprise customers, including those with the highest of security demands, such as the Department of Defense,” wrote Windows in a blog post.