HELP! My computer has strange DNS problems.

[j.erbes]

My Ethernet-connected desktop can resolve only about 30% of the sites that I try to visit. The problem is just with my desktop computer. I don't have any problems If I plug the desktop's Cat-5 cable into my laptop, so it is not a problem with my ISP (AT&T U-verse). My desktop is running Win 10 Pro 64. 10.0.17134

Some of the sites I CAN access include:
google.com, att.com, facebook.com (no sound), wikipedia.com, youtube.com (no sound), CDC.com, NIH.com, mozilla.org.

Some sites I CAN'T access include:
yelp, newegg.com, ebay.com, amazon.com, my Yahoo mail server, download.mozilla.org, and a whole bunch of various other sites.

Note that I CAN access mozilla.org, but I CAN'T access download.mozilla.org

The message I get for about 70% of the sites I try is:
"We can't connect to the server at xxx.xxx.xxx"

These are the things I have tried that have not worked:
1. PING - I can't PING anything, not even my own router or NIC. I get no response when I PING. It just sits there and does nothing. This may be the most important clue to the problem. My other computers can PING anything with no problem.
2. It is not within Firefox or Internet Explorer. They both give identical results or non-results.
3. Multiple reboots don't help.
4. I ran System File Checker and it came back clean.
5. I changed the IPv4 DNS addresses on the Ethernet card to Google's 8.8.8.8 and 8.8.4.4. I also changed the IPv6 DNS addresses to Google's. This initially seemed to fix the problem three weeks ago, but it doesn't help now.
6. I did a "Restore Firewall to Default" in Windows Defender. That didn't help.
7. Temporarily turning off Windows Defender Firewall didn't help either.

There is something wrong with this particular computer but I can't figure out what it is.

 

[popatim]

Have you tried changing your DNS to another one?
I've been on Cloudlfare for about a year and before that it was google's for several years.
These are all FREE!

Cloudfalre 1.1.1.1 & 1.0.0.1
Google 8.8.8.8 & 8.8.4.4
OpenDNS 208.67.222.222 & 208.67.220.220
Comodo 8.26.56.26 & 8.20.247.20
Norton 199.85.126.10 & 199.85.127.10

 

[j.erbes]

Have you tried changing your DNS to another one?

Yes, I did try that but it didn't help. I also tried a DNS flush.

 

[bill001g]

You can test to see if this is really a DNS issue or something else with the NSLOOKUP command. You can easily see what the name server is responding with.

It might be a IPV6 issue. There still after all these years is little reason to use IPv6. I would disable it in the nic settings completely.

 

[Peter Martin]

sounds like you were hacked... lol i remember having to reset winsock... what a pia, this is worth a try

• 
  ■ At the command prompt, run the following commands in the listed order, and then check to see if that fixes your connection problem:
  ■Type netsh winsock reset and press Enter.
  ■Type netsh int ip reset and press Enter.
  ■ Type ipconfig /release and press Enter.
  ■ Type ipconfig /renew and press Enter.