How to Fix ‘Your DNS Server Might Be Unavailable’ in Windows 11

Few Windows networking errors cause as much confusion as the message “Your DNS server might be unavailable”. When this error occurs, your network icon may display an exclamation point or globe symbol, web browsers fail to load domains with errors like DNS_PROBE_FINISHED_BAD_CONFIG, yet your local router and other Wi-Fi devices continue working normally.

This message signifies that Windows 11 can establish a physical link to your router or access point, but cannot translate human-readable domain names (such as google.com) into numerical IP addresses. This practical tutorial explains how to resolve the error by flushing local DNS resolver caches, resetting the Winsock catalogue, and configuring trusted, high-performance public DNS servers.

Method 1: Flush DNS Cache and Reset the TCP/IP Stack

In most instances, corrupted hostname resolution tables or outdated DHCP leases inside the Windows networking stack cause the system to query an unresponsive resolver.

1. Click the Start button, type cmd, right-click Command Prompt, and select Run as administrator.
2. Purge the local DNS resolver cache by entering:

   ipconfig /flushdns

3. Release your current local IP configuration from the router:

   ipconfig /release

4. Request a fresh IP address and DNS server assignment:

   ipconfig /renew

5. Reset the low-level Windows Socket (Winsock) catalogue:

   netsh winsock reset

6. Reset the TCP/IP stack to default settings:

   netsh int ip reset

7. Restart your computer to finalise the network interface reset.

Method 2: Switch to Public DNS Servers (Cloudflare or Google)

Many internet service providers (ISPs) supply default DNS servers that suffer from intermittent downtime, latency spikes, or aggressive filtering. Manually assigning reliable public DNS addresses circumvents ISP server outages entirely.

1. Press Windows + I to open the Settings app.
2. In the left navigation menu, click Network & internet.
3. Click on your active connection type: Wi-Fi or Ethernet.
4. Click on Hardware properties (or click directly on your connected Wi-Fi network name).
5. Locate the DNS server assignment row and click Edit.
6. Change the drop-down menu from Automatic (DHCP) to Manual.
7. Toggle on the IPv4 switch.
8. In the Preferred DNS field, enter:

   1.1.1.1

   (or 8.8.8.8 for Google DNS).
9. In the Alternate DNS field, enter:

   1.0.0.1

   (or 8.8.4.4 for Google DNS).
10. Click Save. Windows will immediately begin routing all domain lookups through the new servers.

Method 3: Restart the Windows DNS Client Service

The background Windows DNS Client service manages all hostname resolution for running applications. If the service enters an unresponsive state, domain lookups will stall.

1. Press Windows + R to open the Run dialogue box.
2. Type services.msc and press Enter.
3. Scroll down the alphabetical list to find DNS Client.
4. If the Restart button is greyed out (as it often is in recent Windows 11 builds for security isolation), launch an elevated Command Prompt and run:

   net stop dnscache && net start dnscache

5. If access is restricted by Windows permissions, restarting your PC achieves the identical clean initialization of the dnscache service.

Method 4: Disable Fast Startup to Force a Clean Network Driver Init

Windows 11 includes a feature named Fast Startup that puts the kernel and hardware drivers into a hybrid hibernation state when you shut down. This can cause network card drivers to wake up with corrupt routing tables.

1. Press Windows + R, type control, and press Enter to open Control Panel.
2. Set the “View by” menu in the top right to Large icons, then click Power Options.
3. In the left sidebar, click Choose what the power buttons do.
4. Click the link near the top that reads: Change settings that are currently unavailable.
5. Under “Shutdown settings” at the bottom, untick Turn on fast startup (recommended).
6. Click Save changes, then perform a complete restart of your PC.

DNS Troubleshooting Reference Table

Use the reference guide below to match connection errors with the most effective fix:

Indicator	Probable Root Cause	Primary Resolution
“DNS server might be unavailable”	ISP upstream DNS failure or stale cache	Switch adapter to Cloudflare DNS (1.1.1.1)
DNS_PROBE_FINISHED_NXDOMAIN	Corrupted local DNS resolver cache	Run ipconfig /flushdns in Command Prompt
Works on Ethernet, fails on Wi-Fi	Adapter power-saving or sleep desync	Disable Fast Startup and reinstall Wi-Fi driver
Fails across all devices on home network	Router DNS proxy daemon crashed	Power cycle home router/modem for 60 seconds

Preventing Future DNS Availability Failures

Maintaining configured secondary and tertiary DNS servers ensures continuous internet availability even if your primary provider suffers an unexpected outage. By pairing Cloudflare (1.1.1.1) as your preferred server with Google DNS (8.8.8.8) as your alternate, Windows 11 gains automated failover protection for seamless browsing.