Can't access from half of the computers on our network.

Hi. Having an issue where about half of the computers on our network cannot access  DNS does not seem to be the issue, as nslookups bring up the right server IP's, tracert works fine.  But... no browsing to the front page on the site from some PC's.  I have tried browsing directly to the IP addresses (listed below), but no go from the problematic PC's.

Adding to Trusted sites does not help. Checked to see if our external IP was on any block lists, but nothing shows up. ipconfig -flushdns made no difference.

NSLOOKUP response is below:      2573      IN      A      2573      IN      A      2573      IN      A

????? Can't think of anything else. Browsing to name or IP seems to work from everywhere else I have tried, just not from some computers on this network! Have also tried disabling windows firewall, no change.

All PCs are Windows 7 Pro. Problem happens in both IE9 and Firefox.

Thoughts appreciated, ran out of ideas.

Who is Participating?
Chris HConnect With a Mentor Infrastructure ManagerCommented:
Can you install chrome and test.  Make sure you're putting the www in front of it, just for kicks.  

Post a screen shot of what you're receiving as far as "internet explorer cannot find the page" or whatever error you're receiving.  

YOu can test ssl connectivity from one of the clients by doing the following:
Chris HInfrastructure ManagerCommented:
I also had an issue where clients could not visit any https:// website from nlite/vlite imaged machines.  It turned out that one of the AIO packs from had some corrupted IE files.  Just throwing that out there...

The fix was to go into add/remove programs and uninstall IE8 update.

Also, make sure you check time on clients.  SSL is time sensitive.
bta-guyAuthor Commented:
Its not an SSL issue, as the front page ( is not secured.  www in front makes no difference.  

Installing Chrome now on one of the machines, although I have doubts that will make a difference as I have tried Firefox.  Worth a shot though.

As for errors, IE just goes to the Bing search page, no error comes up.  Firefox says:

Server not found
          Firefox can't find the server at

  Check the address for typing errors such as instead of
  If you are unable to load any pages, check your computer's network
  If your computer or network is protected by a firewall or proxy, make sure
    that Firefox is permitted to access the Web.
bta-guyAuthor Commented:
Chrome returns:

Oops! Google Chome could not find
Try reloading

Addtional suggestions:
-Access a chached copy of
-Search on Google
bta-guyAuthor Commented:
Thanks for your responses everyone, figured it out. OUr ISP had us make a DNS change to a few PC's while troubleshooting a problem last week. Some PC's were never changed back. So, still not sure why, as they were getting good DNS info, but those PC's were changed back to "Obtain DNS" and all works fine.

Thanks again. Points for all!
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