In my new home, I sometimes face power failures while working on my computer, which never happened to me before. After restarting, the internet connection stops working on that particular computer, but other devices can still use the same connection without any issues.
I am certain that it is a DNS issue because when I try to ping a URL, it fails, but if I use the IP address, it responds. I have attempted several fixes, such as flushing the DNS, resetting the internet connection, and even a system restore, but none of them have worked. The only solution that seems to work is reinstalling or doing a factory reset, which is time-consuming and inconvenient, given how often this issue occurs.
Initially, I thought it might be a hardware problem, but I have experienced it on different computers. It seems to be related to power interruptions, as one time my computer froze, and when I rebooted it, I encountered the same problem.
Although I have only experienced this problem since the power issues began, I have seen that many people are facing the same problem across different versions of Windows, including Win 7, 8, 8.1, and Win 10.
Do you have any suggestions? This problem has occurred again, and I don’t want to spend an entire day reinstalling everything.
3 Answers
Understanding the Issue of Windows DNS after Power Outages
Power outages can be a frustrating experience, especially if you are working on your computer. While power outages can cause hardware issues, they can also create software problems that may be difficult to diagnose. One such issue is the Windows DNS problem that occurs after a power outage.
When a power outage occurs, the computer may shut down abruptly without warning, causing the operating system to shut down improperly. This can corrupt system files or cause data loss, including DNS cache. DNS (Domain Name System) is responsible for translating web addresses into IP addresses, allowing computers to find and connect to websites.
When DNS cache is corrupted or lost, the computer may not be able to connect to the internet, even though other devices on the same network can. This is because the computer cannot resolve the IP address of the website.
Fixing the Windows DNS Issue after a Power Outage
If you are facing the Windows DNS issue after a power outage, there are several fixes you can try before resorting to a system restore or reinstalling Windows.
1. Restart the DNS Client Service
The DNS Client Service is responsible for resolving DNS requests on your computer. Sometimes, the service may stop working, causing the DNS issue. To restart the DNS Client Service, follow these steps:
1. Press the Windows key + R to open the Run dialog box.
2. Type “services.msc” in the box and press Enter.
3. Scroll down and find the DNS Client Service.
4. Right-click on it and select Restart.
2. Flush the DNS Cache
Flushing the DNS cache can clear any corrupted or outdated entries, allowing the computer to connect to the internet. To flush the DNS cache, follow these steps:
1. Press the Windows key + R to open the Run dialog box.
2. Type “cmd” in the box and press Enter.
3. Type “ipconfig /flushdns” and press Enter.
4. Wait for the command to complete and try connecting to the internet again.
3. Reset the TCP/IP Stack
Resetting the TCP/IP stack can also fix the Windows DNS issue after a power outage. To reset the TCP/IP stack, follow these steps:
1. Press the Windows key + R to open the Run dialog box.
2. Type “cmd” in the box and press Enter.
3. Type “netsh int ip reset” and press Enter.
4. Wait for the command to complete and restart your computer.
4. Update Network Drivers
Outdated or corrupted network drivers can also cause the Windows DNS issue after a power outage. To update network drivers, follow these steps:
1. Press the Windows key + X and select Device Manager.
2. Expand the Network adapters section.
3. Right-click on your network adapter and select Update driver.
4. Follow the on-screen instructions to update the driver.
5. Disable IPv6
Disabling IPv6 can also fix the Windows DNS issue after a power outage. To disable IPv6, follow these steps:
1. Press the Windows key + R to open the Run dialog box.
2. Type “ncpa.cpl” in the box and press Enter.
3. Right-click on your network adapter and select Properties.
4. Uncheck the box next to Internet Protocol Version 6 (TCP/IPv6).
5. Click OK and try connecting to the internet again.
Preventing Windows DNS Issue after a Power Outage
While the above fixes can help resolve the Windows DNS issue after a power outage, it is always better to prevent the issue from occurring in the first place. Here are some tips to prevent the Windows DNS issue after a power outage:
1. Use a UPS
A UPS (Uninterruptible Power Supply) can provide backup power to your computer in case of a power outage, allowing you to shut down your computer properly. This can prevent data loss or corruption, including DNS cache.
2. Use a Surge Protector
A surge protector can protect your computer and other devices from power surges that can damage hardware or corrupt software. It is recommended to use a surge protector for all electronic devices, including computers.
3. Enable DNS Client Service Automatic Startup
Enabling the DNS Client Service automatic startup can ensure that the service is always running, even after a power outage. To enable DNS Client Service automatic startup, follow these steps:
1. Press the Windows key + R to open the Run dialog box.
2. Type “services.msc” in the box and press Enter.
3. Scroll down and find the DNS Client Service.
4. Right-click on it and select Properties.
5. Under the General tab, change the Startup type to Automatic.
6. Click OK and restart your computer.
4. Use a UPS for Network Devices
If you have a network device, such as a router or modem, it is recommended to use a UPS for them as well. This can prevent network interruptions or downtime, allowing you to stay connected to the internet even during a power outage.
5. Backup Important Data
It is always a good practice to backup important data regularly, especially before a power outage. This can prevent data loss or corruption, including DNS cache.
Conclusion
The Windows DNS issue after a power outage can be frustrating, but it is not a hardware issue and can be fixed with the above methods. It is also important to prevent the issue from occurring in the first place by using a UPS or surge protector, enabling DNS Client Service automatic startup, using a UPS for network devices, and backing up important data regularly. With these tips, you can ensure that your computer stays connected to the internet even during a power outage.
It’s possible that the power interruption is causing corruption in the DNS cache or other system files that are related to the network connection on your computer. Here are some steps you can try to troubleshoot and resolve the issue:
- Restart your router and modem: This can help reset the connection and potentially resolve any issues with the DNS.
- Flush the DNS cache: You can do this by opening a command prompt and typing “ipconfig /flushdns” (without quotes). This will clear any stored DNS information on your computer.
- Reset the network adapter: You can do this by going to the Control Panel, selecting “Network and Internet,” and then clicking on “Network and Sharing Center.” From there, click on “Change adapter settings” on the left side of the window, right-click on the network adapter you are using, and select “Disable.” Wait a few seconds and then re-enable the adapter.
- Reset the TCP/IP stack: You can do this by opening a command prompt and typing “netsh int ip reset resetlog.txt” (without quotes). This will reset the TCP/IP stack on your computer and potentially resolve any issues with the DNS.
- Check for malware: It’s possible that malware on your computer could be causing the DNS issues. You can use a reputable antivirus program to scan your system and remove any detected malware.
- Check for updates: It’s also possible that there could be an issue with the network drivers on your computer. You can check for updates by going to the manufacturer’s website or by using Windows Update.
I hope these steps help resolve the issue. If the problem persists, it may be helpful to contact your internet service provider or a computer technician for further assistance.
TLDR: In my case, the issue was caused by a VPN setup using OpenVPN, which left behind DNS routing policies after a power loss. I had to manually remove the registry entry to resolve the problem.
In more detail, I am facing the same problem with my Windows 10 laptop (the battery is disconnected, but that’s a separate issue). After a power outage, the DNS stops working, although the internet connection seems to be working fine. I can connect to other hosts using their IP address, and DNS lookup works properly in WSL applications. This problem affects both wired and wireless networks.
To find the root cause, I used Wireshark and noticed a large number of DNS requests being sent to an invalid IP address on my local network. Searching for this IP address in regedit, I found that it appeared under…
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Dnscache\Parameters\DnsPolicyConfig\OpenVPNDNSRouting-0
and
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Interfaces\{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}
It’s evident that the issue was related to a DNS policy set up by my VPN. I made a backup of both keys in the registry and deleted them, which immediately restored the DNS functionality.
To give the full context, I had OpenVPN running before the power loss, which had a DNS routing policy to route private network hostname lookup through a DNS server over the VPN. When the power loss occurred, OpenVPN was unable to unregister the policy. Upon system restart, the DNS routing policy was still in effect, but the VPN was not yet connected since it was unable to connect to the VPN gateway using the hostname instead of the IP address.