A Windows 11 update installs, the computer restarts—and suddenly the internet stops working.

Wi-Fi may still say:

Connected

Ethernet may still show a link.

Other devices in the office may work normally.

Yet the updated PC cannot:

• open websites
• connect to Microsoft 365
• access network drives
• reach cloud applications
• use Teams or Outlook normally

When this happens immediately after a Windows update, the problem may involve the Windows networking configuration, a network driver, VPN software or another networking component rather than the router or broadband service.

One useful repair is to reset the Windows network stack.

But don't start there blindly.

First establish which part of the connection is actually broken.

First: Is the Internet Really Down?

Test another device on the same network.

Use another computer or phone and open several websites.

If nothing works

Investigate shared infrastructure such as:

• router
• firewall
• broadband connection
• switch
• wireless access point
• ISP outage

Resetting one Windows PC's networking will not repair an office-wide outage.

If other devices work

The problem is likely specific to the updated computer.

That makes Windows, its network adapter, driver or installed networking software much stronger suspects.

Restart Windows Properly First

Before changing anything, perform:

Start > Power > Restart

Don't simply shut the PC down and turn it on again.

Windows Fast Startup can mean shutdown and startup do not perform exactly the same full system reload as Restart.

A normal restart can clear temporary driver and service problems without requiring any deeper intervention.

If the connection returns, stop there.

Check the IP Configuration

Open Command Prompt or Windows Terminal and run:

ipconfig

Find the active Wi-Fi or Ethernet adapter.

A normal business or home network may give the PC an address such as:

192.168.1.64

or:

10.0.0.84

If you instead see:

169.254.x.x

that is an important clue.

Microsoft says an address in the 169.254.x.x range indicates that Windows failed to obtain an IP address from the router or DHCP service.

That suggests investigating:

• DHCP
• network driver
• Wi-Fi connection
• Ethernet cable
• switch port
• adapter configuration

rather than immediately blaming DNS.

Reset the Windows Network Stack

Microsoft's current Windows Ethernet troubleshooting guidance recommends running the following commands in this order.

Open:

Windows Terminal (Admin)

or:

Command Prompt (Admin)

Then run each command separately.

1. Reset Winsock

netsh winsock reset

Winsock provides the interface Windows applications use to communicate with network services.

Microsoft says winsock reset returns the Winsock catalogue to a clean state and removes custom Layered Service Provider entries that can contribute to corrupted networking behaviour.

Problems can sometimes arise after changes involving:

• VPN software
• network security products
• proxy tools
• filtering software
• malware
• damaged networking components

A successful reset normally tells you to restart Windows.

Complete the remaining commands first.

2. Reset TCP/IP

Run:

netsh int ip reset

This resets TCP/IP configuration used for Windows networking.

It can help where the PC has problems involving:

• IP addressing
• default gateway
• routing
• DHCP communication
• damaged network configuration

If some lines report an error or Access Denied, don't immediately start modifying Registry permissions.

Finish the supported troubleshooting sequence, restart and test first.

3. Release the Current IP Address

Run:

ipconfig /release

Windows gives up the DHCP address currently assigned to its network adapters.

The connection may appear to disappear temporarily.

That is expected.

On a PC with multiple adapters, you may also see messages relating to:

• disconnected Ethernet
• VPN adapters
• virtual switches
• Bluetooth networking

Those do not necessarily indicate a problem.

4. Request a New IP Address

Run:

ipconfig /renew

Windows now asks the DHCP server for fresh network configuration.

That should normally provide:

• IP address
• subnet information
• default gateway
• DNS servers

If /renew fails and the computer receives a 169.254.x.x address, the PC still isn't successfully communicating with DHCP.

That becomes the next thing to investigate.

5. Flush the DNS Cache

Run:

ipconfig /flushdns

Microsoft includes this as the final command in its current Windows network troubleshooting sequence.

It clears locally cached DNS information so Windows must obtain fresh name-resolution results.

This is especially useful when:

networking works by IP address but websites fail by name.

Restart the PC

Now choose:

Start > Power > Restart

Allow Windows to start normally and reconnect to Wi-Fi if necessary.

Then test the connection properly.

Don't Just Open One Website

One website failing does not prove the network is still broken.

Test the connection in layers.

Check the IP Address

Run:

ipconfig

Confirm the PC has a valid address, default gateway and DNS configuration.

Test the Local TCP/IP Stack

Run:

ping 127.0.0.1

This tests the local TCP/IP implementation.

Test the Gateway

Find the Default Gateway from ipconfig.

For example:

ping 192.168.1.1

Use your actual gateway address.

If this works, the PC can at least communicate with the local network gateway.

Test an External IP Address

Try:

ping 1.1.1.1

If an external IP address responds but websites still fail, DNS becomes a stronger suspect.

Remember that not every internet destination responds to ping, so treat this as one diagnostic clue rather than absolute proof.

Test DNS

Run:

nslookup microsoft.com

This shows which DNS server Windows is using and whether it can resolve the hostname.

You can now distinguish:

No valid IP address → DHCP/local connection problem.

Valid IP but cannot reach gateway → local network/adapter problem.

Gateway works but external IP fails → upstream routing, firewall or internet problem.

External IP works but names fail → DNS problem.

That is much more useful than repeatedly resetting everything.

If the Five Commands Don't Fix It

A network-stack reset can repair corrupted Windows networking configuration.

It cannot repair every post-update connectivity problem.

The next step is to find the cause.

Check Windows Update Again

Open:

Settings > Windows Update

Look for:

• another cumulative update
• pending restart
• failed update
• optional driver
• follow-up fix

If the problem began immediately after a specific Windows update, record the KB number.

That is particularly important if several similar PCs develop the same fault.

One machine failing could be local.

Twenty identical machines failing after the same KB deserves investigation at the update level.

Check the Network Adapter Driver

Windows updates sometimes coincide with network-driver changes.

Open:

Device Manager > Network adapters

Find the active Wi-Fi or Ethernet adapter.

Look for:

• warning symbols
• recently changed driver date/version
• disabled adapter
• duplicate or unexpected adapters

If the adapter appears present but broken, uninstalling the device and restarting can allow Windows to detect it again. Microsoft includes network-adapter driver removal/reinstallation among its supported troubleshooting steps.

When uninstalling the device, don't automatically remove the driver package unless you already have a known-good replacement available.

Use the Manufacturer's Driver

For business devices, I'd normally check the PC or motherboard manufacturer's support channel.

That may mean:

• Dell
• HP
• Lenovo
• ASUS
• Acer
• Microsoft Surface

The manufacturer may have validated a driver against that model's:

• firmware
• docking station
• power management
• chipset

Avoid generic third-party “driver updater” tools.

They can make a simple network problem considerably harder to diagnose.

Check VPN Software

VPN clients install network adapters, routes and filtering components.

An outdated VPN component can sometimes interfere with Windows networking after an update even when the VPN does not appear to be actively connected.

Try:

• updating the VPN client
• fully exiting it for a controlled test
• checking for old unused VPN software
• reviewing virtual adapters
• reinstalling the approved VPN client where justified

Do not permanently remove a required corporate VPN simply because it restores internet access.

If disabling it fixes the problem, you've found something useful to investigate.

Check Endpoint Security and Network Filters

Security products can also install network filtering drivers.

If connectivity disappeared after a Windows update, check whether your security platform has:

• a pending update
• compatibility warning
• damaged filter driver
• required restart
• service failure

Do not simply turn off managed endpoint protection indefinitely.

On a business PC, involve the administrator or IT provider.

Check Proxy Settings

Open:

Settings > Network & internet > Proxy

If your organisation does not intentionally use a proxy, check for an unexpected manually configured one.

You can also run:

netsh winhttp show proxy

On a standard direct internet connection, WinHTTP may report direct access.

But do not remove corporate proxy configuration unless you understand why it is present.

Wi-Fi Only? Forget and Reconnect

If Ethernet works but Wi-Fi doesn't, the Windows networking stack as a whole probably isn't the only issue.

Go to:

Settings > Network & internet > Wi-Fi > Manage known networks

Select the affected network and choose:

Forget

Then reconnect using the correct password.

This rebuilds the saved wireless profile.

Ethernet Only? Check the Physical Link

If Wi-Fi works but Ethernet doesn't, check:

• cable
• switch/router port
• dock
• USB Ethernet adapter
• negotiated link speed

A network-stack reset cannot repair a damaged Ethernet cable or failed docking station.

Test with a known-good cable and another port before making more Windows changes.

When to Use Windows Network Reset

Windows also provides:

Settings > Network & internet > Advanced network settings > Network reset

This is a broader operation than the command sequence.

Microsoft describes Network Reset as a last-step troubleshooting option because it removes installed network adapters and reinstalls them with default settings.

Afterwards you may need to restore:

• Wi-Fi configuration
• VPN software
• static IP addresses
• virtual network adapters
• Hyper-V networking
• specialist network configuration

So record important settings first.

Don't use Network Reset when the evidence already points to something simpler such as DNS or a bad driver.

Business PCs: Be Careful With Static IP Addresses

Most ordinary laptops use DHCP.

Some business systems do not.

Servers, specialist workstations or equipment may have manually configured:

• IP address
• subnet mask
• gateway
• DNS servers

A broader Network Reset can disturb these settings.

Before resetting a business device, record its current network configuration.

What looks like:

“Windows broke the internet”

can become:

“We accidentally erased the specialist application's static network configuration.”

Should You Roll Back the Driver?

If connectivity stopped immediately after a network-driver update and the previous driver worked correctly, Device Manager may offer:

Roll Back Driver

That can be a useful diagnostic test.

If rollback fixes the problem, look for a newer corrected driver rather than simply remaining on an older release indefinitely.

Should You Uninstall the Windows Update?

Not as the first step.

Security updates exist for a reason.

Only consider a controlled rollback when:

• the issue began immediately after a specific update
• normal troubleshooting failed
• the problem is reproducible
• multiple similar devices are affected
• there is credible evidence the update is responsible

For business devices, manage the response centrally rather than leaving individual employees on indefinitely deferred security updates.

When It Isn't Windows at All

A network-stack reset will not repair:

• failing Wi-Fi hardware
• damaged Ethernet port
• faulty cable
• failing dock
• broken access point
• router failure
• ISP outage

Hardware becomes more likely when:

• Wi-Fi disappears completely from Device Manager
• the adapter repeatedly disconnects
• Ethernet says no cable is connected with several known-good cables
• a USB network adapter works while the internal device does not
• manufacturer diagnostics report failure

Follow the evidence.

Don't Use Random Registry Fixes

Avoid troubleshooting sequences that begin with:

• deleting unknown Registry keys
• permanently disabling networking services
• installing network “repair” utilities
• disabling security software
• removing system drivers without replacements

Microsoft already provides supported commands and a built-in Network Reset option.

Use those before making undocumented changes to Windows.

The Fastest Diagnostic Order

When Windows 11 loses internet connectivity after an update:

1. Test another device on the same network.
2. Restart Windows properly.
3. Run ipconfig.
4. If the issue is specific to the PC, run the five Microsoft network commands.
5. Restart again.
6. Check whether Windows has a valid IP address.
7. Test the gateway.
8. Test an external IP address.
9. Test DNS with nslookup.
10. Check the network driver.
11. Review VPN, proxy and endpoint-security software.
12. Check Windows Update for a follow-up fix.
13. Use Network Reset only if simpler troubleshooting fails.
14. Investigate hardware if the adapter or physical connection itself is unstable.

The important principle is:

Reset the stack when the evidence points to Windows networking—but don't use it as a substitute for diagnosis.

How Hamilton Group Can Help

A Windows update should improve security and reliability, not leave employees unable to work.

Hamilton Group can help diagnose:

• Windows 11 networking failures
• Wi-Fi and Ethernet problems
• DNS and DHCP faults
• network-driver issues
• VPN connectivity
• Microsoft 365 access
• firewall and security configuration
• Windows Update problems
• business network infrastructure

If one laptop loses connectivity after an update, the problem may be local.

If an entire group of managed PCs develops the same problem simultaneously, the better approach is to identify the common driver, update or policy rather than repairing each computer independently.

Visit hgmssp.com or call 0330 043 0069 to speak with Hamilton Group.