Oracle Database Discussions

I see similar posts, but I have not understood the solutions. This is my first installation of a DB. I'm taking a class that requires db 10g, and I'm trying to load it on my home computer. Windows XP pro. Everything seemed to be going well, until the point where it is suppose (by the instructions I'm following) to configure a new user account. When the URL:http://localhost:5500/em is suppose to open to the login page it gives me the following error page

The database status is currently unavailable. It is possible that the database is in mount or nomount state.


If I hit the "Startup" button I get the following page...

Startup/Shutdown:Specify Host and Target Database Credentials
Specify the following credentials in order to change the status of the database.

It wants "Host Credentials" with username and password that no matter what I put in, it doesn't like. What are the "Host" Credentials?

The installation I'm following is off of this site...

http://www.course.com/cdkit/installinstructions_dbIII.cfm

I can log in to SQL with the default Scott/Tiger - but (and I don't know anything about this really), if the db won't start a lot of good it does me.

Anybody have any suggestions? I can't seem to establish a new user account for 10g, as the db is 'currently unavailable.''

thanks,

Dan