Microsoft Active Directory (User, group and computer management)
Microsoft Windows Desktop and Server Operating Systems - Windows registry, Group Policy, File/folder security concepts (NTFS/share permissions, etc.)
Microsoft SCCM
Infoblox DNS/DHCP Management
Enterprise Backups (Commvault/Rubrik)
Citrix Workspace/XenDesktop Virtual Desktop
VMware vSphere
Core networking concepts (DNS, DHCP, etc.)
Any Graduate