Website- Help!!!!!!!!!!

I am trying to set up a webpage using the built in server in XP Pro. I installed the IIS service and client on my computer. I made my pages using Dreamweaver and then I saved the in the wwwroot folder. I made a dynamic DNS name so that I could get a name for my computer that would point that name to my computers IP address. When I try to access my page from the computer that I made it on, by typing in http://"my DNS name", I can get to the page and all of the links work. But when I try to get to my page from another computer by trying in that same address, a "This page could not be Displayed" page pops up. I am using dial- up on my computer for about the next week then I will be switching to Cable internet. I installed a service that automatically updates my IP address for my DNS name. What can I do to make thisa work???? I checked with my ISP to see if port 80 was blocked and it was not, I even tried changing the port that I use and it still did not work. I also forwarded the port on my router. I can access the site from any computer on my network. Help!!!!!!!!!!!!!!!!!!

Thanks