Administers, maintains, secures, and troubleshoots Windows servers, physical hosts, virtual machines, workstations, and other endpoint systems across closed networks, sites, and operational environments, providing host-based systems administration and engineering support for a DoD customer responsible for the secure, reliable, and uninterrupted operation of mission-critical IT infrastructure, including: Manage Microsoft server infrastructure across multiple solution areas, including Windows Server, Active Directory, DNS, DHCP, Group Policy, virtualization, file/print services, and enterprise management platforms. The successful candidate will bring hands-on expertise administering, securing, and modernizing Windows Server environments, Active Directory, and virtualization platforms within a DoD enterprise setting, along with a proven track record of planning and executing upgrades, migrations, and system modernization efforts with minimal disruption to operations.