Installation Accounts and Groups
UNIX uses the concept of a DBA group. The root account cannot be used to install Oracle Database. 
               
A separate Oracle Database account must be created manually.
On Windows, Oracle Database must be installed by a Windows username in the Administrators group. The user name is automatically added to the Windows local group ORA_DBA, which receives the SYSDBA privilege. This allows the user to log in to the database using CONNECT / AS SYSDBA and not be prompted for a password.
               
You can also create an ORA_OPER group to grant SYSOPER privileges to the other Windows users.
               
Password files are located in the ORACLE_HOME\database directory and are named pwdSID.ora, where SID identifies the Oracle Database instance.
               
Related Topics
See Also:
Oracle Database Installation Guide for Microsoft Windows about "Operating System Groups Created During Oracle Database Installation"
Parent topic: Oracle Database Differences on Windows and UNIX