IIS 7 hosted sites not accessible from remote machines

Recently while working on my Vista machine, I was was working on a ASP.NET Web site and I wanted to have a colleage of mine have a look. Like always, I mailed him the URL and waited for him to view it and get back. To my surprise, he reverted stating he can't view it.
The error he was getting was "Internet Explorer cannot display the webpage". This was surprising since I was able to view the site locally on the Vista machine without any issues. This meant that IIS was configured and running properly.

I tried to figure out the reason for this strange behavior since the IIS and world wide web services were all running properly on the machine. Turns out, it isn't really strange after all. It is one of those things done to make your machine more secure. To get this working, you need alter the default Firewall settings.
Run the Windows Firewall Settings Wizard (firewall.cpl) and in the Exceptions tab, scroll down and enable "World Wide Web services (HTTP)" option, as shown in the figure below. You will now be able to access the site properly. There is Support KB also on this, which I later found out.


 Important These steps may increase your security risk. These steps may also make the computer or the network more vulnerable to attack by malicious users or by malicious software such as viruses. We recommend the process that this article describes to enable programs to operate as they are designed to or to implement specific program capabilities. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this process in your particular environment. If you decide to implement this process, take any appropriate additional steps to help protect the system. We recommend that you use this process only if you really require this process.

To allow for remote connections to the Internet Information Services 7.0 Web site, add exceptions to Windows Firewall. To do this, follow these steps:

1. Click Start, type windows firewall in the Start Search box, and then click Windows Firewall in the Programs list.
   
   If you are prompted for an administrator password or confirmation, type your password or click Continue.
2. Click Allow a program through Windows Firewall.
   
   If you are prompted for an administrator password or confirmation, type your password or click Continue.
3. On the Exceptions tab, click to select one or more of the following check boxes, depending on the traffic that you want to allow to visit the Web site:
   • FTP Server
   • Secure World Wide Web Services (HTTPS)
   • World Wide Web Services (HTTP)
4. Click OK