Incorrect or Non Existent DNS server on laptop (Windows 7)

Question

I've been trying to fix this issue for a few hours now, and have ran through a large number of troubleshooting lists.

Yesterday my laptop connected to my home network just fine, today it connects, but says "limited access" and no internet connection is available. The ISP is Comcast/Xfinity, but I'm thinking it's a problem on my laptop itself, not with the ISP. When I run the troubleshooting utility, I get a message that says that it is trying to correct to an incorrect or non existent DNS server.

Here's what I've done:

• Manually typed in a static IP address and other connection information such as DNS server and subnet mask (using my router's IP as the DNS server.)
• Restarting the computer
• Disabling/Enabling the wireless adapter
• Flushed DNS cache (ipconfig /flushdns in elevated command prompt)
• Connecting to a friend's fully functional network (I get the exact same issue.)
• Having friends connect to my home network (their computers all connect flawlessly)
• I went out and purchased a netgear USB wireless adapter, disabled my built in one, installed the drivers for the new one, and I still get the exact same issue, down to the same troubleshooting message.
• I have tried to get to the router's management back end via it's IP address (10.0.0.1) to no avail, I just get a connection timed out notification, so I cannot successfully connect to the router's management page.

Does anyone have any ideas of what might be wrong/how to fix it? I'm still googling but so far, after 3 hours straight of troubleshooting I have made no progress.

UPDATE

• sfc /scannow returns no integrity violations
• TCP/IP has been reset from the command prompt
• ipconfig /release and ipconfig /renew have been run
• nslookup / ping have been tried and they both fail
• the hosts file is empty
• I tried using an ethernet cable and hooking directly to the router, i still get the same error

The problem still persists after everything listed here.

Solution

Reset the Internet Protocol (TCP/IP) on the computer. Here is how to do that - How to reset Internet Protocol (TCP/IP).

Then you should probably run Malware Bytes or SpyBot S&D to make sure there isn't anything else (malware/spyware/adware) messing with your system. A free online scan at eSet just to make sure its clean might be a good idea.

Once you know the system is clean, open an elevated command prompt and run SFC /SCANNOW to run the System File Check. When it is done, reboot and see if things are back to normal.

Comments

[Admin]

What happened when you did sfc /scannow from an elevated command prompt? Also, check out superuser.com/a/464014/3463.

[jmreicha]

So this may potentially be a bad network card. Does it work when connected directly to the router? Are there any strange entries in your hosts file?

[without_margin]

I will get back to you guys on this as soon as I can get back to my laptop, thanks for helping!

[without_margin]

@jmreicha I haven't been able to test it with an ethernet cord, but I have installed an entirely new NIC through USB, shouldn't that rule out bad network card?

[jmreicha]

So what are you using for a DNS server? Do an nslookup google.com or something similar and see what DNS servers you get. Were there any entries in the hosts file? Can you ping out to anything on the internet?

[without_margin]

@jmreicha sfc /scannow found no integrity violations, nslookup google.com could not connect to find a dns server, it just continuously timed out and retried. DNS server is currently set to "obtain dns server address automatically", when i tried to set it manually I used my router's IP address (10.0.0.1)

[jmreicha]

Set your DNS to 8.8.8.8 (Google DNS server) and try again. Can you ping outside at all? I'm still curious about the hosts file as well as what happens with a hard connection.

[without_margin]

@jmreicha Just tried a hard connection, and it made no difference, same issue, same error message. The hosts file was empty except for the default comments that are in there, and pinging does not work, I can't get a response from any external addresses.

[jmreicha]

Hm, interesting. Can you get to your router? Try pinging to 10.0.0.1 (assuming that is your router's IP).

[without_margin]

No, I can't get access to the router either

[without_margin]

I was under the impression that if a NIC fails, you can just completely bypass it with another NIC, whether it be USB, PCI, whatever... So if that's true, then how is it possible that another NIC is getting the exact same error?

[without_margin]

@jmreicha I did run diagnostics on RAM and HD, as well as update drivers. In the end I finally gave up and took the thing to a repair shop. By the next day they had fixed the problem and claimed it was a virus. I ran a MalwareBytes scan, a Panda Cloud Antivirus scan, and an eSet scan (all separately and independently, only one was enabled at a time.) and I did not find even a single malicious item.

[without_margin]

I will get back to you in a couple of hours and let you know if this worked. I don't have access to the laptop right now.

[without_margin]

I reset TCP/IP, checked and re-checked to make sure there are no viruses, and ran the SFC /SCANNOW command. TCP/IP reset succesfully | No viruses | /scannow found no integrity violations

[without_margin]

It did end up being a virus, but MalwareBytes, Panda Cloud Antivirus, and eSet all failed to find it. The computer repair shop found it on the first night. Thanks for your help. I'm giving you the answer because you suggested looking for viruses, and no one else answered.

[CharlieRB]

Glad you were able to get it resolved. Did they give you any details as to what virus it was and how they cleaned it? Those details would be helpful to add to your question for others who read it.

[without_margin]

I will update the question as soon as they give me details on the virus.