The database is in mount or nomount state.

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...
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.''


You tried to help me before, and I have the same problem with a differnet computer. The installation goes great until I get to step 13 (listed below). When the Oracle Enterprise Manager 10g Database Control web page opens it tells me that the db is not online. I did what you said in previous posts - except the last post. Am I suppose to do that?
I can't seem to create a new user. Actually I just tried to log on to http://localhost:5500/em and it said the page can't load.
13.     When the End of Installation page displays and confirms that the installation was successful, click Exit, and then click Yes to confirm exiting. The Oracle Enterprise Manager 10g Database Control web page opens.
Configuring a New User Account for the Oracle10g Database
When you start your computer, the Oracle10g database starts automatically, and is ready to accept data requests. Before you can use the Oracle10g database, you must perform some configuration tasks. First you create a user account, which is identified by a user name and password and is associated with an area in the database in which you create your database tables. You create a user account named dbuser, with password oracle.
To create the user account:
1.     On the Oracle Enterprise Manager Database Control Login page, type SYSMAN as the User Name and enter the password you specified in step 6 above, and then click Login.
TIP: If you are not on the Oracle Enterprise Manager Database Control Login page, then open a Web Browser and type the following URL: http://localhost:5500/em
2.     The Oracle Database Licensing Information 10g page will appear. Read the page and scroll to the bottom and then click I Agree. This page appears the first time a new user logs in to the Oracle Enterprise Manager Database Control application.
3.     The Oracle Enterprise Manager Database Control Home page will appear. To create a new user for the Oracle database: orcl, click the Administration link.
4.     Under the Security heading click the Users link.
5.     On the Oracle Enterprise Manager Database Control Users page, click the Create button located on the right hand side of the page.
6.     Type DBUSER in the Name field, oracle in the Enter Password field, and oracle in the Confirm Password field.
7.     Type USERS in the Default Tablespace field and Temp in the Temporary Tablespace field.
8.     Click the Roles link, click the Modify button, select DBA in the Available Roles list, and then click the move arrow so that DBA appears in the Selected Roles list.
9.     Click OK on the Modify Roles page, and then click OK on the Create User page. A message confirms that the object was successfully created.
10.     Click the Logout link at the bottom of the page.
11.     Close the Oracle Enterprise Manager 10g Database Control web page by clicking the X icon in the upper right corner of the web page.
Starting SQL*Plus and Logging On to the Oracle Database 10g
To confirm that you can connect to your Oracle10g database, you now start SQL*Plus and log on to the database using the DBUSER account.
To start SQL*Plus and log on to the database:
1.     Click Start on the Windows taskbar, point to Programs or All Programs, point to Oracle – OraDb10g_home1, point to Application Development, and then click SQL Plus. The Log On dialog box opens and requests your user name, password, and host string.
2.     Type DBUSER in the User Name field, press Tab, type oracle in the Password field, leave the Host String field blank, then click OK. The SQL*Plus program window opens, and the SQL prompt appears.
3.     Close the Oracle SQL*Plus window.