localhost login

I've just upgraded my system from XP Home to XP Pro and
now I can't get to http://localhost:8080 because the
system prompts me to log in. It refuses the .NET
username/password pair specified for my user (Owner) and
it refuses the username/password pair specified for my
Internet connection. I don't need this level of security
because it's just me at home practicing new technologies.

I would like to configure the machine so it doesn't
prompt for a login to get to localhost. If I can't do
this, then at least I need to know what to set for the
username/password pair. Can anyone help with this?
Thanks.

Shelah