To fix an Ethernet driver problem after installing Windows 11 26H2, uninstall the Ethernet adapter in Device Manager with its driver removed, restart so Windows reinstalls it, and roll back or update the driver if that fails. Microsoft's 26H2 known issues list contains no Ethernet or network adapter issue as of September 30, 2026, so the cause is almost always the adapter driver or network settings on your PC.
This guide covers the fastest fix, how to tell a driver fault from a cable or router fault, driver rollback and updates, network reset, and what each Device Manager error code means.
The fastest fix: reinstall the Ethernet adapter driver
Microsoft recommends this approach when a network connection stopped working after a recent update. Download a backup driver from your PC or motherboard maker first, using another device if this PC is offline, and keep it on a USB drive.
- Select Search on the taskbar, type Device Manager and open it.
- Expand Network adapters and find your Ethernet adapter.
- Right-click the adapter and select Uninstall device.
- Tick Attempt to remove the driver for this device, then select Uninstall.
- Select Start > Power > Restart.
- After the restart, let Windows detect the adapter and install a driver automatically.
- If no driver appears, install the backup driver you saved from the manufacturer's website.
Then open Settings > Network & internet and check that Connected shows under the Ethernet connection name.
What Microsoft has confirmed about 26H2 and Ethernet
Knowing what 26H2 changed narrows down why a wired connection broke after the update.
| Fact | What it means for Ethernet |
|---|---|
| 26H2 known issues at launch: USB audio devices, domain trust with Credential Guard, black screen in virtual desktops | No Ethernet, network adapter or driver issue is on Microsoft's 26H2 list |
| On 24H2 and 25H2, 26H2 arrives as enablement package KB5121794 on a shared code base | The networking stack is the same one your PC already ran; the update switches on features rather than replacing Windows |
| Windows removes default kernel trust for cross-signed drivers | Drivers from the Windows Hardware Compatibility Program and an allow list of trusted legacy drivers keep working; an old cross-signed network driver may not |
| Windows audits driver compatibility for at least 100 hours and three restarts before enforcing | An old driver can stop loading some days after the update, not immediately |
Other open problems are among the 26H2 known issues, and the KB5121794 enablement package itself changes little on disk.
Which fix matches your symptom
| What you see | Start with | Why |
|---|---|---|
| Ethernet adapter shows a yellow warning or error code in Device Manager | Reinstall the driver, then roll back or update it | The driver failed to load or start |
| Adapter missing from Network adapters | Action > Scan for hardware changes, then a manufacturer driver | Windows has no driver installed for it |
| Adapter looks fine, but Settings shows Action needed or no internet | Cable, router and network commands | The driver works; the connection or IP settings do not |
| Problem began right after a driver update | Roll Back Driver | Restores the previous driver version |
| Nothing else worked | Network reset | Reinstalls every adapter with default settings |
| Wi-Fi also fails | The general 26H2 no-internet fixes | The fault is not specific to the Ethernet driver |
For a problem that hits Wi-Fi as well, work through the 26H2 no internet fixes instead.
Rule out the cable and router first
A loose cable looks exactly like a dead driver. These checks take two minutes and come from Microsoft's own Ethernet troubleshooting order.
- Check that the cable is firmly in the Ethernet port on the PC and on the router, and that it uses a LAN port, not the router's Internet port.
- Swap in another Ethernet cable if you have one.
- Unplug the router and the modem, wait at least 30 seconds, plug the modem in, wait for its lights to settle, then plug the router in.
- Connect the PC to Wi-Fi, if it has it, to see whether the internet itself works.
- Plug another PC or a USB to Ethernet adapter into the same cable; if that fails too, the router or provider is at fault, not Windows 11 26H2.
Roll back the Ethernet driver
Use this when the connection broke right after Windows installed a new network driver. The option only works if a previous driver version exists.
- Open Device Manager.
- Expand Network adapters.
- Right-click your Ethernet adapter and select Properties.
- Select the Driver tab, then select Roll Back Driver.
- Restart the PC.
If Roll Back Driver is greyed out, Windows has no older driver stored; use the reinstall or update method instead. The same approach fixes other driver faults after the update, such as the Realtek audio driver fixes.
Update the Ethernet driver through Windows Update
Windows Update installs recommended drivers automatically, but optional driver updates wait until you pick them. Manufacturers publish certified drivers there.
- Select Start > Settings > Windows Update > Advanced options.
- Make sure Receive updates for other Microsoft products is turned on.
- Under Additional options, select Optional updates.
- If a network driver is listed under driver updates, select it and select Download and install.
- Restart the PC, even if the update did not ask for it.
If Windows Update has nothing, download the latest driver for your Windows version from the PC or motherboard maker's website. Driver dates can look old; Windows chooses drivers by the maker's targeting data, not the date.
Update the Ethernet driver in Device Manager
- Download the manufacturer's Ethernet driver for your model and unpack it to a folder.
- Open Device Manager and expand Network adapters.
- Right-click the Ethernet adapter and select Update driver.
- Choose to browse your computer for drivers and point it at the folder you unpacked.
- Follow the on-screen instructions and restart the PC.
Use drivers only from the PC maker, the motherboard maker or the network chip vendor. Never use a third-party driver updater.
Reset TCP/IP and renew the IP address
When the adapter shows no error but still gets no connection, reset the network stack. Select Search, type Command prompt, then select Run as administrator > Yes.
netsh winsock reset
netsh int ip reset
ipconfig /release
ipconfig /renew
ipconfig /flushdnsRun the five commands in this order, pressing Enter after each. They reset Winsock and the TCP/IP stack, release and renew the IP address from the router, and flush the DNS client cache.
You should see: ipconfig /renew lists your Ethernet adapter with an IPv4 address from your router, and web pages load again.
Use network reset as the last step
Network reset removes every network adapter and its settings, then reinstalls them with defaults after a restart. Microsoft lists it as the last thing to try.
- Select Start, open Settings and select Network & internet.
- Select Advanced network settings > Network reset.
- Select Reset now, then Yes to confirm.
- Wait for the PC to restart and test the Ethernet connection.
Afterwards, reinstall VPN clients and recreate Hyper-V virtual switches if you use them. Known networks may switch to the public profile, which hides the PC from other devices on the network until you set it back to private.
How to check the Ethernet driver is working
- Open Settings > Network & internet and confirm Connected appears under the Ethernet connection name.
- Open Device Manager, expand Network adapters and confirm the Ethernet adapter has no warning icon.
- Right-click the adapter, select Properties and check that the Device status area shows no error code.
- Open a website to confirm traffic flows, not just the link.
To confirm the PC really moved to the new version, check that 26H2 is installed.
Fix Ethernet adapter error codes in Device Manager
Find the code under Device status in the adapter's Properties. These are the codes Microsoft documents that point at a driver.
"This device cannot start. (Code 10)"
The driver could not start the adapter.
- In the adapter's Properties, select the Driver tab, then Update Driver.
- Point it at the manufacturer's latest driver if Windows asks for a path.
- Restart the PC.
"The drivers for this device are not installed. (Code 28)"
No driver is installed for the adapter.
- Right-click the adapter in Device Manager and select Uninstall.
- Select Action on the menu bar, then Scan for hardware changes.
- Supply the manufacturer's driver if Windows cannot find one.
"Windows has stopped this device because it has reported problems. (Code 43)"
The adapter's driver told Windows the device failed.
- Uninstall the adapter in Device Manager.
- Select Action > Scan for hardware changes to reinstall it.
- If the code returns, check the hardware documentation or contact the PC maker.
"Windows cannot verify the digital signature for the drivers required for this device. (Code 52)"
The driver is unsigned or damaged; an old cross-signed driver that Windows no longer trusts by default is one possible source.
- Download the latest driver for Windows 11 from the adapter or PC manufacturer.
- Install it with Update driver in Device Manager.
- Contact the manufacturer if no signed driver exists for your adapter.
"This device is disabled. (Code 22)"
Someone disabled the adapter in Device Manager.
- Select the adapter in Device Manager.
- Select Action > Enable Device and follow the wizard.
"A driver can't load on this device" notification
Memory integrity in Windows Security is blocking a driver with a known vulnerability.
- Note the driver and company name shown in the notification.
- Check Optional updates in Windows Update and the manufacturer's website for a compatible driver.
- Keep memory integrity on; ask the manufacturer when a fixed driver is due if none exists.
If a USB to Ethernet adapter never appears at all, the port may be the problem; the 26H2 USB detection fixes cover that side.
When the driver cannot be fixed: go back or repair
- Contact the PC or adapter maker and ask whether a Windows 11 driver is planned for your adapter.
- Use Wi-Fi or a supported USB to Ethernet adapter in the meantime.
- If Windows files are damaged, reinstall the current version of Windows while keeping files and apps.
- If the problem started with a full upgrade and the PC is still within the rollback window, go back to the previous version from Settings > System > Recovery.
The repair route means repairing 26H2 without losing files, and the rollback route means uninstalling 26H2 safely.
Frequently asked questions
Does Windows 11 26H2 break Ethernet drivers?
Microsoft has not listed any Ethernet or network adapter problem among the 26H2 known issues as of September 30, 2026. Wired connection faults after the update usually trace to the adapter driver or network settings, which a driver reinstall, rollback or network reset fixes.
Why did my Ethernet stop working days after the 26H2 update?
Windows now removes default trust for old cross-signed kernel drivers and audits compatibility for at least 100 hours and three restarts before enforcing it. An outdated network driver can therefore stop loading later. Install a current, certified driver from the manufacturer.
How do I reinstall the Ethernet driver in Windows 11 26H2?
Open Device Manager, expand Network adapters, right-click the Ethernet adapter and select Uninstall device. Tick Attempt to remove the driver for this device, select Uninstall and restart. Windows reinstalls a driver automatically after the restart.
How do I install an Ethernet driver without internet?
Download the driver from the PC or motherboard maker's website on another device and copy it to a USB flash drive. On the offline PC, open Device Manager, right-click the adapter, select Update driver and browse to the folder on the USB drive.
Why is Roll Back Driver greyed out?
Roll Back Driver only works when Windows still holds a previous version of the driver. If the option is greyed out, no older driver is stored, so reinstall the adapter or install the manufacturer's driver through Update driver instead.
Will network reset delete my files?
No. Network reset removes and reinstalls network adapters and returns their settings to defaults. It does not touch personal files, but you may need to reinstall VPN software, recreate Hyper-V virtual switches and set trusted networks back to private.
Should I turn off memory integrity to load my old network driver?
No. Microsoft's first recommendation is an updated, compatible driver through Windows Update or the manufacturer. Turning memory integrity off weakens protection against malicious drivers, and on a Secured-core PC it takes the device out of its Secured-core state.
If a PC has no working network yet, there are offline routes for installing 26H2 without an internet connection.
