HI I'm having some trouble hosting on w3
I know its not my fire walls fault because I turned it of and still can't host
Can any 1 tell me what to do now

Are you connected to a router? If you are, you need to enable port forwarding on the router to get to your computer. Otherwise, when people try to connect, they get to the router, and it doesn't know what to do with them, so it just ignores them.

Hmmm but I don't know whether I am using a router or modem.and if I am really using a router how do I enable port forwarding on the router for other people to get to my com?please teach me the methods because I really wan to create game and host it on my own

Here si the info you need for Warcraft III (select your router form the list)
PortForward.com - Free Help Setting up Your Router or Firewall (http://portforward.com/english/applications/port_forwarding/Warcraft_III/Warcraft_IIIindex.htm)