The Department of Defense (DoD) has commenced an enterprise-wide deployment of Microsoft's Windows 10 operating system as part of an effort to bolster IT security and standardize processes, Microsoft announced in a blog post.

Attributing the news to the Office of DoD CIO Terry Halvorsen, Microsoft said that Secretary of Defense Ashton Carter had directed all DoD agencies currently on legacy operating systems to immediately begin migrating to Windows 10. This upgrade will affect approximately four million devices and systems, and is slated for completion in one year— “an unprecedented move for a customer with the size and complexity of the DoD,” the blog post states.

In a Nov. 20, 2015 memo, Halvorsen addressed the planned implementation of Windows 10, explaining the decision was to “improve our cybersecurity posture, lower the cost of IT and streamline the IT operating environment.”