ORA-01031: insufficient privileges on Windows sqlplus "/as sysdba"

Issue: 

C:\Windows\system32>sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Mon Aug 1 20:43:55 2016

Copyright (c) 1982, 2010, Oracle. All rights reserved.

ERROR:

ORA-01031: insufficient privileges

Solution:

è Verified user to be part of ORA_DBA group, which is missing below

c:\Oracle>echo %username%

surajarajuj

C:\Windows\system32>NET LOCALGROUP ORA_DBA

Alias name     ORA_DBA

Comment        Oracle DBA Group

Members

----------------------------------------------------------

NT AUTHORITY\SYSTEM

The command completed successfully.

C:\Windows\system32>NET LOCALGROUP ORA_DBA  suraparajuj /add

The command completed successfully.

C:\Windows\system32>NET LOCALGROUP ORA_DBA

Alias name     ORA_DBA

Comment        Oracle DBA Group

Members

--------------------------------------------------------

NT AUTHORITY\SYSTEM

DBHOST\suraparajuj

The command completed successfully.

c:\Oracle>sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Mon Aug 1 20:43:55 2016

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 – Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

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