How to change lost password or oracle sys account

Products

• Data Loss Prevention Endpoint Prevent

Issue/Introduction

Unable to run oracle_create_user.sql due to the sys accounts password is unknown 

Environment

Release : oracle 12c, oracle 19c

Component : Windows

Cause

invalid password

Resolution

1. Edit the sqlnet.ora located at %ORACLE_HOME%\network\admin\

1. change the sqlnet.authentication_services = (NTS)
2. add the logged in user to the local group ora_dba

1. launch command prompt 
   1. run command sqlplus /nolog
   2. run command conn / as sysdba;
   3. alter user sys identified by [new password];