windows server 2003/2008/2008r2/2012/2012r2, advanced server technologies, including failover clustering, network load balancing, hyperV, GPO, exchange, ISA/TMG servers (vpn, firewall, publishing, etc), office communication server 2007 r2, lync 2010/2013, IIS, active directory, DNS, DHCP, WSUS, WDS. iSCSI, HP proliant and blade servers, HP various storage.