IIS 7.5 – Fixing Access Issues Working Only from Localhost

I have seen this a few times and it is usually caused by an incorrect proxy server configuration. If you can access it via telnet (this would not be going via the proxy) then you have effectively verified that a service of some kind (not necessarily IIS!) is running on that port.

I recommend disabling the auto-detect proxy option if you are using Internet Explorer and are not using a proxy or if you must use a proxy add explicit declarations for exceptions rather than relying on the "Bypass Proxy for Local Addresses" checkbox.

It's not real clear if you are running on a sever or a desktop. I'm assuming you are running on a desktop with Visual Studio. If that is the case, the built-in Visual Studio web server, "Cassini" does not accept remote connections AT ALL! Try downloading IIS Express or actually spinning up IIS on your machine instead, those will allow remote connections.

Aslo, your explanation of switching from Apache to IIS because of Integrated Authentication to the Database doesn't make much sense. Why not just use the MSSQL drivers for your language that support MSSQL? Here is the PHP site: http://blogs.msdn.com/b/sqlphp/

Provide more detail next time and you will get a better response.

UPDATE: Based on your clarifications the following is where I would start...

1. Is the default website turned on? If so the default bindings there are *:80, so all requests on port 80 get served by the server. Test to make sure at a minimum you get the IIS Welcome page when accessing it remotely. If so then....
2. Check the IIS Site Bindings, at it's simplest level make sure that your website/application accepts *:80, so all traffic on port 80. This will conflict with the default web site so turn that off first.

If that doesn't work you may have some underlying issues either with the firewall, double check it is truly off or has the HTTP excetion turned on and then I would look to DNS and or Network issues after that.