Hardware maintenance /repair (desktops, laptops, UPS); Assembly /disassembly /replacement of components (RAM, HDD /SSD, PSU, motherboard); Windows /Linux (Ubuntu, CentOS) installation /troubleshooting; Network setup /management (LAN /WAN, IPv4 /IPv6, DNS, DHCP); Router /switch /access point /firewall /port forwarding configuration; Cat5e /Cat6 cable crimping, patch panel setup /labeling; Printer /scanner /biometric installation /troubleshooting; Diagnostic tools (multimeters, cable testers, ping, traceroute, CLI).