Oracle On Windows - sysdba user is getting error ORA-01017: invalid username/password; logon denied

Oracle On Windows - sysdba user is getting error ORA-01017: invalid username/password; logon denied

Issue:
Windows administrator user is unable to connect to database as sysdba user using OS authentication

C:\Users\Administrator>set ORACLE_HOME=E:\app\mallik\product\19.0.0.0\dbhome_1

C:\Users\Administrator>set ORACLE_SID=ORA19C

C:\Users\Administrator>E:\app\mallik\product\19.0.0.0\dbhome_1\bin\sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Wed Jul 31 20:29:34 2024

Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.

ERROR:

ORA-01017: invalid username/password; logon denied

Enter user-name:

ERROR:

ORA-01017: invalid username/password; logon denied

Enter user-name:

ERROR:

ORA-01017: invalid username/password; logon denied

SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus

C:\Users\Administrator>

Cause: 
Administrator user is not port of ORA_DBA group 

Solution or Fix:
Add administrator user to ORA_DBA group 

Edit local users and groups 

-> add administrator user to ORA_DBA group