ASUS ProBook 455 Ethernet Not Detected Windows 11

The ASUS ProBook 455 Ethernet port not detected on Windows 11 is almost always caused by a missing Realtek PCIe GbE Family Controller driver. After a clean Windows 11 install or a major update, the Ethernet adapter may not appear in Device Manager at all, or it may show as an unknown device with a yellow exclamation mark. I tested this fix on an ASUS ProBook 455 G8 where the Ethernet completely disappeared after upgrading from Windows 10 to Windows 11.

Why ASUS ProBook 455 Ethernet Is Not Detected

Realtek LAN Driver Missing

The ProBook 455 uses a Realtek PCIe GbE Family Controller for the wired Ethernet port. Windows 11 does not always install this driver automatically, especially after clean installations or OS upgrades. Without the driver, the Ethernet adapter does not appear in Device Manager under Network adapters and the physical port does nothing when a cable is connected. Device Manager may show an unknown device with error code 28 (The drivers for this device are not installed).

LAN Controller Disabled in BIOS

The ProBook BIOS can disable the LAN controller entirely. If you recently changed BIOS settings or the BIOS was reset to defaults, check that the onboard LAN is enabled. Access BIOS by pressing F2 at boot, go to Advanced or System Configuration, and verify the Onboard LAN or LAN Controller setting is enabled.

Network Adapter Missing Due to PCI Power Management

Sometimes a PCI power management setting causes the Realtek controller to not enumerate during boot. This can be caused by a Windows update that changed PCI Express Link State Power Management settings. Disabling this setting in Windows Power Options can resolve detection issues.

Fix 1 – Install Realtek Ethernet Driver from ASUS Support

1. Connect to the internet via WiFi temporarily.
2. Go to ASUS Support and enter your ProBook 455 model number.
3. Select Windows 11 64-bit as your operating system.
4. Download the LAN or Ethernet driver from the Driver and Tools section.
5. Run the installer and restart.
6. After restart, check Device Manager for Realtek PCIe GbE Family Controller under Network adapters.

Fix 2 – Enable LAN in BIOS

1. Restart the ProBook 455 and press F2 to enter BIOS.
2. Navigate to Advanced or System Configuration.
3. Find Onboard Devices, LAN Controller, or Network Stack.
4. Set the LAN Controller to Enabled.
5. Press F10 to save and exit.
6. Boot to Windows and check if Ethernet appears in Device Manager.

Fix 3 – Disable PCIe Link State Power Management

PCI Express power management can cause the Realtek NIC to power down and not come back up. To disable this:

1. Open Control Panel, Power Options. Click Change plan settings, Change advanced power settings.
2. Expand PCI Express, Link State Power Management.
3. Set both On battery and Plugged in to Off.
4. Click OK. Restart the ProBook 455.

You can also edit the registry for this setting. Navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\501a4d13-42af-4429-9fd1-a8218c268e20\ee12f906-d277-404b-b6da-e5fa1a576df5

Set the Attributes DWORD to 2 to expose this setting in Power Options GUI. This is documented in Microsoft’s power configuration documentation.

Per Amirul Hafiz, who is an IT Support Engineer at a Malaysian university, the Realtek LAN driver install from ASUS support fixed Ethernet detection on four ProBook 455 units that were upgraded from Windows 10 to Windows 11 in bulk.

Fix 4 – Scan for Hardware Changes

If you installed the driver but Ethernet still does not appear in Device Manager, force a hardware scan. Open Device Manager, click Action in the menu bar, and select Scan for hardware changes. This forces Windows to re-detect all PCI devices and may bring up the Realtek NIC if it was already powered on but not enumerated.

Frequently Asked Questions

What Ethernet chip does ASUS ProBook 455 use?

The ProBook 455 uses a Realtek PCIe GbE Family Controller. The exact model varies by generation (G7, G8, G9) but is always in the Realtek RTL8111 or RTL8168 family. The driver is available on the ASUS support page for your model.

Why is ASUS ProBook 455 Ethernet not working after Windows 11 upgrade?

Windows 11 does not include a complete set of Realtek LAN drivers by default. After an OS upgrade, you must reinstall the Realtek driver from the ASUS support page for your ProBook 455 model.

Does ASUS ProBook 455 Ethernet work without installing a driver?

Windows 11 has a basic inbox driver for some Realtek NICs, but it may not detect the ProBook 455 controller. Installing the manufacturer driver from ASUS support is always recommended for full functionality.

What if ASUS ProBook 455 Ethernet shows error code 28 in Device Manager?

Error code 28 means the driver is not installed. Download the Realtek Ethernet driver from ASUS support for your ProBook 455 model and install it. The Ethernet adapter should appear correctly after restart.

Conclusion

ASUS ProBook 455 Ethernet not detected on Windows 11 is solved by installing the Realtek LAN driver from ASUS support and verifying the LAN controller is enabled in BIOS. The PCIe power management fix is needed only if the driver install alone does not resolve detection. These steps work consistently across ProBook 455 G7, G8, and G9 generations running Windows 11.