When you connect a device to your home network or a Wi-Fi hotspot with internet access, the internet connection may fail to work for a variety of reasons.
Instructions in this article apply to Windows 10, Windows 8, and Windows 7.
Reasons Why You Cannot Connect to a DNS Server
One class of failures are related to Domain Name System — the distributed name resolution service used by internet providers around the world. Windows 7, Windows 8.1 and Windows 10 computers may report the following error messages in the Troubleshooting Problems found window:The DNS server isn't respondingYour computer appears to be correctly configured, but the device or resource (DNS server) is not responding
The device will not be able to reach the internet when these failure conditions occur. These DNS server errors may appear for any of several different reasons. Step-by-step network troubleshooting steps can be used to diagnose and repair the problem as described below.
How to Run Windows Network Troubleshooter in Windows 10
On Microsoft Windows PCs, Windows Network Diagnostics can be run to help diagnose internet connection problems. If you're not sure whether or not your computer is reporting DNS Server Not Responding errors, follow these steps:
Select Start and then choose Settings.
Select Network & Internet. The Network Status window will open.
Select Network Troubleshooter under Change Your Network Settings. Windows Network Diagnostics will open.
Follow the steps to begin and wait for the troubleshooting tests to complete. The wizard will offer customized diagnostic assessments based on the errors it thinks it finds, so each pass-through will differ for different people. Look in the Problems found section of the window for the error message to better identify potential root causes.
How to Run Windows Network Troubleshooter in Windows 7 or 8
Open the Control Panel.
Open the Network and Sharing Center.
Click the Troubleshoot problems under Change your Networking Settings.
Click Internet Connections. A new Internet Connections window appears.
Click Run the Troubleshooter.
Click Troubleshoot my connection to the Internet.
Wait for the troubleshooting tests to complete and look in the Problems found section of the window for the error message.
You should be done!
How to Fix DNS Server Not Responding Problems
To properly fix these internet connection failures requires first isolating the problem down to its root cause. The sections below each cover common causes of these failures:
Misbehaving internet provider
Malfunctioning TCP/IP or DHCP services
Overly aggressive antivirus software
Malfunctioning router or modem
If not confident that your internet connection issues are truly related to DNS, try general connection troubleshooting techniques first.
Resolving TCP/IP and DHCP Failures
It's possible for the TCP/IP software inside a client device's operating system to malfunction and set its DNS server addresses incorrectly. Rebooting a Windows computer often clears these temporary glitches. A more elegant solution involves running TCP/IP utility programs that perform the standard procedure to release and renew the Windows IP address settings.
Similarly, most TCP/IP networks use the Dynamic Host Configuration Protocol service to assign IP addresses to clients. DHCP assigns not only the device's private IP address but also primary and secondary DNS server addresses. If DHCP is malfunctioning, a PC reboot is likely required to recover it.
Check to ensure both your device and the network router both have DHCP enabled. If either end of the connection is not using DHCP, internet connection errors normally result.
Handling DNS Provider Problems
Many people configure their home networks to automatically obtain DNS server addresses from their internet provider. When the provider's servers or network suffer an outage or are heavily loaded with traffic, their DNS services can suddenly stop working. Customers must wait until the provider fixes those problems before they can use the provider's DNS.
As an alternative to the private DNS servers supported by each provider, several providers, most notably Google and OpenDNS, offer free public DNS servers. A router administrator can switch their network's DNS setup over from a private to a public DNS configuration by manually entering the public DNS IP addresses into the router configuration settings.
DNS settings can also be applied on the Windows device itself through the Network and Sharing Center. However, this approach usually will not work as a permanent solution because devices normally obtain and override their local settings with those from the router through DHCP.
Avoiding Internet Blockages from Antivirus Programs
Antivirus programs that people install on their Windows PCs are designed to keep intruders out, but they also block internet access if they detect a misbehaving device.
Most antivirus programs work using special database files that the software vendors automatically update on a regular basis. PC users often don't realize when these install updates happen as they are triggered in the background and designed to not interrupt normal work.
Unfortunately, sometimes mistakes are made with these data updates that cause the antivirus program to believe a computer is infected when really it is a false alarm (false positive test). These false positives can trigger Windows to suddenly start reporting DNS Server Not Responding errors.
To verify whether this is the cause for your device, temporarily disable the antivirus program and re-run the Windows Network Diagnostics. Then consult the antivirus vendor for either a new update or technical support. Although disabling antivirus does not work as a permanent solution, doing so to temporarily to troubleshoot the problem is normally (not always) safe.
Recover or Replace a Malfunctioning Router or Modem
A misbehaving broadband router or broadband modem can trigger these DNS error messages on home network devices. Restarting the router and modem will resolve intermittent router glitches, at least temporarily.
Routers and modems must eventually be replaced if they continue to exhibit failures. However, it is unlikely for either to fail in such a way that would cause DNS errors to be regularly generated. Failed routers and modems normally cannot power on at all or else generate errors related to the underlying network connection itself. If you connect to the router using a wired Ethernet port, try moving the Ethernet cable to use a different port instead.