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Hardware

Set Up a 2.5GbE PCIe Network Adapter on Windows 11

Install a 2.5GbE network card, load the correct driver, and verify Ethernet link speed.

by@guidox updated:10/29/26 time:30 min level:Intermediate works on:Windows 11 25H2 x64, PCIe 2.5GbE Ethernet adapters
⚠ Safety notice

Incorrect hardware installation can damage components. Disconnect power and follow the manufacturer's installation instructions.

TL;DR

Install a compatible **2.5GbE network card** and confirm that Windows negotiates the expected Ethernet speed.

Before you start

Requirements

  • Windows 11 25H2 x64
  • Available compatible PCIe slot
  • 2.5GbE PCIe network adapter
  • 2.5GbE-capable switch or router port
  • Suitable Ethernet cable
  • Manufacturer driver if required
Step by step

Instructions

01

Check network hardware

Verify that the adapter fits an available PCIe slot and that the connected network equipment supports 2.5GbE.

02

Install the adapter

Power down the PC, disconnect power, and install the card according to the motherboard and adapter manuals.

03

Connect Ethernet

Attach the adapter to a compatible network port using a suitable cable. Start Windows.

04

Install the driver

Open **Device Manager** and check the network adapter. Install the manufacturer's supported driver if Windows does not configure it automatically.

05

Check link negotiation

Open the Ethernet connection properties and check **Link speed**. Confirm it reports the expected negotiated rate.

06

Test network transfers

Transfer a large file between devices capable of exceeding gigabit speeds. Compare the observed throughput with your network hardware limits.

tipAn internet speed test cannot prove local 2.5GbE performance if your internet plan is slower.
Troubleshooting

Common issues

The adapter connects at 1Gbps.

Check the switch port, cable, and adapter driver. Leave speed negotiation on automatic unless the vendor recommends otherwise.

The adapter is missing from Device Manager.

Power off and reseat the card. Verify PCIe slot compatibility and firmware detection.

FAQ

Frequently asked

Do I need a 2.5GbE router?

The connected port or switch must support 2.5GbE to establish that link speed.

Can Windows 11 use two Ethernet adapters?

Yes. Windows can detect and configure multiple network interfaces.

How to undo this

Disconnect the network cable, uninstall any adapter-specific software, shut down the PC, and remove the card. Reconnect the original network adapter.

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