Experience supporting Microsoft Windows environments , including Windows Server 2008–2022, Windows 10/11, Exchange, Active Directory, DNS, Group Policy, PKI, workstation/server hardware, backup, antivirus, DHCP, and TCP/IP. Overview: AMERICAN SYSTEMS, a 100% employee-owned federal government contractor, is seeking a motivated, customer-focused Senior Systems Administrator to provide Tier II operational support for a high-visibility customer mission.