What would cause a computer to fail to make any high level network connections?

I thought it could not hurt to ask while I am having a slow work day.

I have a computer that is running Windows 7 64-bit Home Premium. Originally I was going to do a repair install of the Windows system files and go about repairing like that. But now I am trying to find out what is really causing the issue.

Basically this is the breakdown, the machine boots up and logs in with no issue. No error messages or anything in the event log that would indicate an error.

I am able to use network tools such as ping, tracert, nslookup and etc.

What does not work however is anything that seem to utilize TCP(possibly UDP also, but nslookup works). If I try to connect to the internet using a web browser of any kind it fails to see anything. I have tried Chrome, and IE.

If I go to a name based URL like www.google.com it says I am not connected to the internet. If I try to connect directly to an IP address it says the same thing. I am not able to get into the router that the machine gets its DHCP lease from. But I am able to get a DHCP lease which is odd.

I have also tried non-web browser based tasks such as updating the anti-virus on the machine (NOD32). The AV says it cannot connect to the update servers.

I have banged my head over this for some time now and have made little to no progress.

What I have tried (Not in order);

Disabling Windows Firewall
Scan with NOD32 bootdisk made from known clean machine
Run Windows SFC / scannow
Checked HOSTS / LMHOSTS file for oddities
Use netsh to reinstall the network stack on (all) network adapters
Use a wired connection instead of wireless
Also tried using a static network address

possibly more I can't recall right now.

Can anyone provide any ideas? This one is bugging me.

Thanks in advance.

ianc1215

Posted 2014-05-02T17:42:08.163

Reputation: 2 884

Please add the type of router,review the copy of your hosts file and also check your dns settings. – Rudolph – 2014-05-02T17:49:03.487

What exactly do you consider "high level" network connections? – Ramhound – 2014-05-02T17:50:11.237

Can you make TCP connections on the local network? For instance, can you load your home gateway's web admin UI in a web browser?

If you can ping a certain Internet host, try pinging it with full-sized frames and with the "Don't Fragment" bit set, in case there's an MTU problem where small frames are getting through, but full-sized frames are getting dropped.

Are other computers on the same network able to use the Internet fine?

< – Spiff – 2014-05-02T18:25:13.613

@Spiff cannot connect to ANY website. I am able to ping things like google.com and 8.8.8.8. I will try your idea when I get home. – ianc1215 – 2014-05-02T18:38:20.520

@Spiff Yes other computer get on the Internet with no trouble. All passing through the same gateway. They also get their DHCP leases from the same router. One is a laptop with Win 7, the other is an XP box. – ianc1215 – 2014-05-02T18:39:28.787

@Ramhound What I am referring to is anything higher than ICMP protocol. – ianc1215 – 2014-05-02T18:40:26.533

@Rudolph The type of router is a WRT54G-v6 with DD-WRT firmware. The DNS servers are set to OpenDNS, I have also used Google Public DNS. – ianc1215 – 2014-05-02T18:41:37.800

Did you try starting Windows in safe mode with networking already? Do you get the same issues when you perform a clean boot? What happens if you boot a non-Windows operating system, e.g. any Linux live distribution?

– and31415 – 2014-05-02T21:55:07.420

@and31415 Not sure about Linux, but when I run in WinPE the networking operates just fine. It is something specific with that Windows installation. – ianc1215 – 2014-05-02T22:42:44.850

Answers

I don't know if you did this already, as it's not listed, but run some malware scans. Run Malwarebytes, Hitman Pro, etc. I have seen in the past where there is something blocking, as you say, the "higher network connections." I have usually found remnants of things like Conduit and other things that cause this issue. If you have already run scans and everything comes up clean, then nvm.

3ngin33r

Posted 2014-05-02T17:42:08.163

Reputation: 69

I did not run MalwareBytes, because the machine has a paid AV (NOD32) on it. While I did not consider malware as possibility I will return to the possibility and try running MalwareBytes. If suspect viruses I usually do run that. I ran NOD32 sys rescue CD/USB in WinPE mode. That way NOD32 has 100% access to the FS nothing is locked or in use. In that mode the system was able to connect and download updates from the update server. NOD32 found nothing. – ianc1215 – 2014-05-02T18:46:58.463

I ran malwarebytes and it found things. But when I tried to get on the internet with a browser or update anything the connection still failed. – ianc1215 – 2014-05-03T22:47:55.793

So it looks like NOD32 missed something or was being disabled. I ran MalwareBytes from herin's boot cd and I found 21 things that were crawling around. Got rid of them but still needed a system repair because something was damaged. – ianc1215 – 2014-05-04T05:51:53.887

Go into the network adapter and give it a fixed IP address, subnet mask,gateway and DNS address. See what happens.

user76732

Posted 2014-05-02T17:42:08.163

Reputation: 573

Tried that one too. No dice. The subnet on the network is 192.168.1.1 so I assigned it 192.168.1.5. – ianc1215 – 2014-05-02T18:36:36.667

I hope that you made a mistake on this. For example, on one of my systems the IP is 192.169.1.100 THE SUBNET IS 255.255.255.0 The gateway is 192.168.0.1 The DNS is from OpenDNS and is 208.67.222.222 – user76732 – 2014-05-04T00:45:36.777

1No, 255.255.255.0 is a subnet MASK. The subnet would be 192.168.1.0. But anyhow the system is working again a repair installed fixed it. Case closed! – ianc1215 – 2014-05-04T05:49:57.390