You can connect to Oracle using the users 'sys', '/ as sysdba' or any database user. The default Oracle port is 1521.
In the Database SID field enter the Oracle SystemId, namely the Oracle instance. Default Oracle SID is ORCL. This identifies the database in case more instances of Oracle are running at one time. You can execute show parameter instance_name in SQLPLUS and see the SID as the last keyword is the list.
Download Oracle 10g from: http://www.oracle.com/technetwork/database/express-edition/downloads/102xewinsoft-090667.html
Start the installation process...Select Next...Accept the license agreement...Select the destination folder:
Type in your password: