Installed Oracle XE 11.2. How do I create a database?
Oracle 11 does not use containers so you already have a database and the default users such as sys and system and all the other oracle built in users.

Go to Computer Management/Local Users and Groups and verify that the group ora_dba exists.
Assuming this is a development project add your regular windows username to the ora_dba group. Now you can log on as sysdba using these steps:


open a command window
enter SET ORACLE_SID=XE
enter sqlplus / as sysdba


This should get you logged on as sys which you should not do normally.  For this one time create a user and grant them a role.

CREATE USER &lt; your new user name &gt; IDENTIFIED BY &lt; your new password &gt;;
GRANT DBA to &lt; your new user name&gt;;


Then enter exit to close the session.  Log on as your new user using Toad and you should be good to go.

I note that the operating system and database are out of support and you would be better off using the new 18xe on linux.