How to change the router access

[fufengfrank]

I am trying to build my own website, I installed IIS in my XP pro system and when I use other computers under the same router use http://myIPaddress/index.htm to vist the files in my computer's wwwroot folder, it is fine. But when someone else's computer not under the same router try to vist my web pages, there is nothing shows up. I am not sure it is because of the router or not. If it is because the router, how can I fix it.

 

[Praetor]

But when someone else's computer not under the same router try to vist my web pages, there is nothing shows up. I am not sure it is because of the router or not. If it is because the router, how can I fix it.

They have to access via the external ip http://externalip/index.htm