DNS Server not responding.

[REDACTED]

I have two laptops on my home network.  Both connect with WiFi.  Both are Dell Inspiron 15's, but one is 7000 series and the other is 5000 series.  Both run Avast Free.   The 5000 series started showing "No Internet" in the browsers.  Windows network troubleshooting says DNS Server not responding.   I went through everything suggested about DNS problems, but I skipped the disable your antivirus, since the same one was running on the other laptop.  Anyway, problem persisted with both onboard adapters ( ethernet and wifi ) disabled and a USB wifi adapter added.  It would run to load a browser after rebooting ( no matter which adapter I was using ), but after a few minutes, the DNS server not responding appeared.  Finally, I disabled AVAST, and everything worked.  I started to uninstall Avast and it gave me the option of "repairing" the installation, so I chose that.  Did not work, so I uninstalled AVAST.  Now all is working fine, but I really like AVAST, and would like to find a way to continue using it.  All suggestions will be appreciated.

[bob3160]

I have two laptops on my home network.  Both connect with WiFi.  Both are Dell Inspiron 15's, but one is 7000 series and the other is 5000 series.  Both run Avast Free.   The 5000 series started showing "No Internet" in the browsers.  Windows network troubleshooting says DNS Server not responding.   I went through everything suggested about DNS problems, but I skipped the disable your antivirus, since the same one was running on the other laptop.  Anyway, problem persisted with both onboard adapters ( ethernet and wifi ) disabled and a USB wifi adapter added.  It would run to load a browser after rebooting ( no matter which adapter I was using ), but after a few minutes, the DNS server not responding appeared.  Finally, I disabled AVAST, and everything worked.  I started to uninstall Avast and it gave me the option of "repairing" the installation, so I chose that.  Did not work, so I uninstalled AVAST.  Now all is working fine, but I really like AVAST, and would like to find a way to continue using it.  All suggestions will be appreciated.

Avast free or paid? Which version. What other Security related software is installed?
Try the following and see if that helps.

Clean Install of Avast:
https://goo.gl/4Ptzkf
If you need additional help with the Clean Install, watch this:
https://youtu.be/p-h3myRD51A

[REDACTED]

Thanks for your reply.  It was Avast Free.  The only other security is Windows Defender.  I think the laptop came with McAfee, but I am not sure, since it was uninstalled almost as soon as we began to use the laptop.  I was planning to re-install Avast, but I didn't know about the "remover".  I will use it for the Avast, and I will also search the registry for McAfee and if I find any references, I will use the "remover" appropriate for it as well.  I am still very curious as to how and why this happened.  Being the free version, it should have NOT had the Secure DNS function.  Wanting to know for the future on my wife's laptop, as well as preventing this from happening with mine as well.

[bob3160]

This will help you get rid of your previously installed AV:
How to Successfully Install Avast: http://goo.gl/VLXde