Network Adapter Not Found: Causes and Solutions

What Does the "Network Adapter Not Found" Error Mean

The "Network adapter not found" error occurs when the operating system cannot detect a network interface—whether onboard or external (USB). The system either does not see the device at the hardware level, or the driver cannot interact with it. The error text may vary:

• Windows: "Network adapter not found", "Device not found", "Error code 31" (driver not loaded).
• Linux: "Device not found", "No such device", "Network is unreachable" when an interface is missing.
• macOS: "Network adapter not found", "No network hardware detected".

Typically, the issue manifests when attempting to connect to a network, the adapter is missing from network settings, or commands like ipconfig (Windows) / ip link (Linux) do not show network interfaces.

Common Causes

The error has several typical causes, ranging from simple to complex:

1. Adapter disabled in BIOS/UEFI. The onboard network controller may be turned off in firmware settings.
2. Corrupted or missing drivers. The driver is not installed, is outdated, or conflicts with other devices.
3. Physical adapter damage. For onboard adapters—issues on the motherboard; for USB—faulty port or cable.
4. Hardware conflict. Multiple network adapters, virtual machines, or software bridges can interfere with detection.
5. OS system file corruption. After a failed update or virus attack.
6. Adapter disabled within the OS itself. In Windows, an adapter can be disabled in Device Manager or network settings.

Solutions

Solutions are presented from simple to complex. Perform the steps sequentially.

Solution 1: Check and Enable the Adapter in BIOS/UEFI

If an onboard adapter is not detected, it may be disabled at the firmware level.

1. Restart the computer and press the key to enter BIOS/UEFI during startup (usually Del, F2, F10).
2. Find the section related to hardware (e.g., Advanced, Chipset, Onboard Devices).
3. Locate the Onboard LAN, Network Controller, or Ethernet option and set it to Enabled.
4. Save changes (通常 F10) and exit.
5. Boot into the OS and check if the adapter has appeared.

💡 Tip: If the adapter is already enabled, try resetting BIOS settings to default (Load Optimized Defaults).

Solution 2: Update or Reinstall Drivers

Drivers are the most common cause. Actions differ for Windows and Linux.

Windows

1. Open Device Manager (Win + R → devmgmt.msc).
2. Expand Network adapters. If the adapter appears with a yellow exclamation mark, right-click → Update driver.
3. Select Search automatically for updated driver software. If Windows doesn't find one, download the driver from the motherboard or adapter manufacturer's website.
4. If the adapter doesn't appear at all, in the Device Manager menu select Action → Scan for hardware changes.

Linux (Ubuntu/Debian)

1. Identify the adapter model:

   lspci -nn | grep -i network
   

   For USB adapters:

   lsusb
   

2. Check if the driver is loaded:

   lspci -k | grep -A 3 -i network
   

   In the output, look for the line Kernel driver in use. If no driver is listed, install the appropriate package. For example, for Realtek:

   sudo apt update
   sudo apt install r8168-dkms
   

3. Reboot the system.

Solution 3: Check Physical Connection (for External Adapters)

If using a USB network adapter:

1. Plug the adapter into a different USB port (preferably directly on the motherboard, not through a hub).
2. Try a different cable (for Ethernet) or a different adapter to rule out hardware failure.
3. In Windows, check if the device is detected in Device Manager under Universal Serial Bus controllers.
4. On Linux, run dmesg | tail after connecting the adapter—messages about device detection should appear in the logs.

Solution 4: System Restore or Roll Back Updates

If the error appeared after an OS or driver update:

Windows

1. Open Control Panel → Recovery → Open System Restore.
2. Select a restore point created before the problem occurred.
3. Alternatively: In Device Manager, right-click the adapter → Properties → Driver → Roll Back Driver.

Linux

If you updated the kernel or drivers, boot into a previous kernel version from the GRUB menu. Or roll back packages:

sudo apt install --reinstall linux-modules-extra-$(uname -r)

Solution 5: Use Diagnostic Tools and Reset Network

Windows

1. Run Network Troubleshooter: Settings → Network & Internet → Advanced network settings → Network troubleshooter.
2. Reset the TCP/IP stack:

   netsh int ip reset
   netsh winsock reset
   

   Restart the computer.

Linux/macOS

1. Check the list of interfaces:

   ip link show
   

   If the adapter exists but is in a DOWN state, bring it up:

   sudo ip link set eth0 up  # replace eth0 with your interface name
   

2. Reinstall network services (macOS):

   sudo ifconfig en0 down  # en0 is typically Ethernet
   sudo ifconfig en0 up
   

Prevention

To avoid recurrence of the error:

• Regularly update drivers from official websites, especially after major OS updates.
• Do not disable the onboard adapter in BIOS unnecessarily. If you need to disable it, do so through OS settings.
• Use quality USB adapters and cables; avoid cheap uncertified devices.
• Create restore points before installing driver or OS updates.
• Check hardware compatibility when upgrading your system (e.g., new graphics cards can conflict with some chipsets).

If the problem persists after all steps, the adapter may be physically faulty. For onboard adapters, consider installing a PCI network card; for USB, replace the adapter.