Dear Sir,
we are not using os authentication
i still have not found the solution with ur post
and perhaps i didn't clear about my query

My Query Was

SQL> connect sys/change_on_install@wizerp as sysdba
ERROR:
ORA-01017: invalid username/password; logon denied

Warning: You are no longer connected to ORACLE.

SQL> conn sys/change_on_install@wizerp
Connected.

Why connection sys as sysdba is not possible?
this is query i put on forum
Can u guide me in this regard?
i hope u won't mind it and help me