Physical checks

  • LEDs on the NIC port — link light (solid) and activity light (blinking). No lights = cable or port issue.
  • Try a different ethernet cable — Cat5e or better.
  • Try a different router/switch port.

Reset network stack

netsh winsock reset
netsh int ip reset
ipconfig /release
ipconfig /flushdns
ipconfig /renew

Driver fix

Device Manager → Network Adapters → right-click the LAN adapter → Update driver. If it shows a yellow error, uninstall and reboot — Windows installs a generic driver. Then get the specific driver from the motherboard manufacturer's support page.

Speed/duplex mismatch

Device Manager → NIC → Properties → Advanced tab → Speed & Duplex. Change from "Auto Negotiation" to "1 Gbps Full Duplex" to force the setting. Mismatch causes intermittent drops.