How to unlock specific User in Oracle Database

Make sure you have installed Oracle Database already installed on your machine. For individual development purpose, Oracle has Express Edition light weight database s/w, that you can download and install on your machine.

- Connect to SQL Command Line prompt
    Start -> All Programs ->  Oracle Database <Version> Edition -> Expand -> SQL Command Line

-  Execute below command
                     SQL> connect / as sysdba

- You should notice as below

- Execute Below commands
          ALTER USER HR IDENTIFIED BY HR;
          ALTER USER HR ACCOUNT UNLOCK;