Sharepoint 3.0: Cannot find a new web application

Hello,
I am searching the internet for hours, found a lot of information,
but I have still the problem.

I have got Sharepoint 3.0 running on a Win Server 2007 SP2.
After the creation of a new web application, I am not able to open the page with the given link:
“Page cannot be found”.

I want to open the page on my server. The server isn’t connected to a network.

Please help me! Thank you from Spain.