We have a server we are currently deploying on, mostly for demoing and
using as a sandbox. I am in the process of building this machine.

What has happened is that if you open a browser window on the server
itself, you are prompted to enter your user name and password and it
works.

However, from anywhere else on the internet, if you enter the web
site, you get a windows sign on box. If you enter your password
incorrectly, it inserts the domain before the user name, and
re-prompts you. I can tell from the security logs that if you enter
the password, you are authenticated.

But then it stops. Sharepoint never returns a web page. I feel like
I have left out some important step, but I cannot figure out what that
step could be. Any ideas? Suggestions for troubleshooting?