Just send the error messages across..
hope u tried
cmd> sqlplus /nolog
>conn / as sysdba
k . hope it helps you.
<b>Enterprise Manager aka OEM? </b>
This is a web page that you should have a link for in you Start | All Programs | Oracle – Ora10 folder. A java command box will appear first when you click it and you do not want to close this box until after you end your OEM session.
When OEM opens the root of the navigation list is the Network, with Databases directly below it. Click the PLUS beside the folder icon to list all the databases that you have in TNSNAMES or you chosen naming method.
<b>IF you have an empty list </b>
It probably means you did not configure any network connections. Go to Oracle -ora10 | Configuration and Migration Tools folder and run the Net Configuration Assistant program to add Listener, Naming Methods, Local Net Service Name and or Directory connections for authentication.