Windows 10 includes built-in (in-box) drivers for most Realtek PCI-E controllers, including the 810X family and the RTL8111 Gigabit family. When you plug in the cable, it usually works automatically.
Uninstall the device in Device Manager, check "Delete the driver software for this device," restart your computer, and let Windows reinstall it.
Reboot after running these commands.
One important limitation: neither the RTL8139 nor the 810x family supports fully in older hardware revisions. Windows 10’s heavy reliance on IPv6 (for Cortana, Store, and updates) can increase CPU usage slightly—by 2–5%, barely noticeable on modern CPUs.
If you installed an RTL810X driver, your hardware is physically limited to 100 Mbps. If you are certain you have a Gigabit card (RTL8111), try this: realtek rtl8139 driver 810x family pci-e gigabit windows 10
Right-click the adapter in Network Connections and choose "Disable," then "Enable."
While the RTL8139 itself is a 10/100 Mbps device, it is often part of a broader Realtek driver package that includes support for newer PCI-E Gigabit controllers (like the RTL8111 series). Driver Compatibility for Windows 10 Windows 10 includes built-in (in-box) drivers for most
Realtek RTL8139/810x Family refers to a classic set of network interface controllers (NICs) primarily designed for 10/100 Mbps Fast Ethernet
Open > Network Adapters > Realtek Properties . Go to the Advanced tab. Scroll down to Speed & Duplex . Reboot after running these commands
Many third-party driver update websites incorrectly lump these hardware IDs together into a single text string to catch all search traffic. If your motherboard has a PCI-E Gigabit slot, you do not have an RTL8139 chip. You have an RTL8111 or RTL8168 chip. How to Identify Your Exact Realtek Card