For some reason my PC will not open a specific URL in any browser (IE, Chrome Firefox or Torch) however when I type the URL into a proxy server page it loads fine.
I can also get the URL in a laptop connected to the same home wifi network.
I’m using Avast free anti virus but don’t see anything wrong here in the settings. I’ve even disabled it while testing.
It’s a work extranet URL so I’m afraid I can’t post it
Advice appreciated!
Why won’t it load, e.g. error message or avast alert, etc. what ?
Without the URL it may be somewhat difficult to pin down the cause. What is your operating system and firewall ?
You say that you have tried it with avast disabled, yet you still have a problem ?
Try to open your URL in Safe Mode + Networking Enable. If that works, your issues may be related with Avast, otherwise you should check for other things.
That may be a bit of a stretch considering the OP has tried with avast disabled in normal mode.
The error message I get when trying to load the page on my desktop PC is -
IE8 - Internet Explorer cannot display the webpage
Firefox - The connection has timed out
My OS is XP Pro x64 Serv Pack 2. The firewall is on.
I’m unable to try it in Safe Mode as it won’t connect to the internet on my wifi.
The URL is 100% and loads fine from my laptop on the same wifi network, but just won’t load at all on my desktop.
The attached may give a better idea of the problem. On the left is the URL being loaded into IE without success. On the right is the same URL being loaded into a proxy server at http://tunnel.freefromall.com/index.php also in IE.
It is only this 1 URL which I’m unable to load (as far as I know) but it’s a particularly important one.
Try changing DNS servers.I had problems with some sites with DNS servers from my ISP.
I am using Norton DNS and Open DNS.You can change them quickly with DNS Jumper.
http://www.sordum.org/7952/dns-jumper-v1-0-5/
Thanks for this abruptum, but I’m a bit wary of changing dns settings and even if it worked, it would be a work around and not a fix.
I’ve never had any problem with the URL before and so there must be an easy solution to resolving it; problem is I just can’t find it 
There is nothing wrong with changing your DNS servers. People do it all the time. I use OpenDNS myself and they even show you how to change it. OpenDNS is probably the best DNS servers.
First you need to rule out if you can reach that URL, using ping command. Than try to access your URL directly from its IP address. Also, to be sure, try an DNS clear, using Start/Run type “ipconfig /flushdns”.
I ran the flushdns command first as that was the easiest (didn’t work)
I then did a reverse ip address, ended up at http://www.ipchecking.com/ and tried http://5.57.16.51/ This did not work either but I double checked the address was correct on my laptop and after a warning about the site being safe, it loaded it so I know its on my PC and not router.
I’m afraid I don’t know how to ping the URL
About PING command forget it, I tried to ping your IP 5.57.16.51, it seems to have blocked ICMP. Take a look at: C:\Windows\System32\drivers\etc. Find “hosts” file and try to open with Notepad. Check there for any suspicious configuration. By default this file is like in attachment.
I don’t think Avast has to do with this issue. In any case, uninstall Avast, and test your page without it. 
Thanks eltonzoto, I’ve tried to check the folder C:\Windows\System32\drivers but to be honest, I don’t really know what to look for or what other folders to check.
I also disabled Avast from the system tray, restarted the PC and tried again but without success; it still won’t load the site.
Do you really think totally uninstalling Avast will make any difference?
Surely there must be a clue in the fact that -
A - it loads on my laptop on the same wifi.
B - it loads when I use a proxy server on the PC.
With regard to the proxy, surely if Avast was the problem it wouldn’t allow it to load?
I still believe the problem is with default DNS servers from your ISP.
In my case sites were also working with proxy.When I changed DNS
servers sites were working fine without proxy server.
Use DNS Jumper,it is easy.You don’t have to install anything,just unzip
file and run DnsJumper.
Hi stephenc,
Regarding Windows hosts file. You must follow this path: [b]C:\Windows\System32\drivers\etc[/b]
where “etc” is directory. Inside “etc” you can find the file called “hosts”. Open it, using
Notepad or any text editor, and check if there are changes compared with default configuration (like in attach image). In many cases, the “hosts” file is object of malwares which modify the basic configuration.
You can try DNSJumper mentioned by abruptum, but IMO, you are using the same ISP, so if the DNS would be the root cause, both computers should have same symptoms. Anyway, rule out this option.
Apologies eltonzoto, I thought by etc you meant other similar drivers :-[
Anyway, I’ve now checked and it says simply -
127.0.0.1 localhost
::1 localhost
Does that mean anything?
Good, that’s the default config.
Btw, have you tried disable Windows Firewall?
In desperation I’ve tried this as the attached image shows and still no joy 
The reason you may have trouble getting there with IE is because the certificate has expired
I thought I’d found the answer here. If I go to Tools | Intenet Options | Security and then click to open Restricted Sites and then click Sites, I get the attached which includes a list of IP addresses with wildcards.
Highlights them and then clicking remove does not work. I did manage to remove a few but quite a few are left. The only problem is that I don’t see the IP address of the problem site and also this is in IE. Surely this would not block IP’s in other browsers?