I recently change my user password and sys password and since I have made these changes I am getting a response of ORA-01034 and ORA-27101 when I try to access sql*plus. I have tried shutting down my PC and restarting and that does not work. I have tried changing the password back but it will not let me do it. And I have even tried performing these steps in a DOS prompt:
SET ORACLE_SID= SANDY
sqlplus / as sysdba
And I am still getting the same error message. At this point I am not sure where to go from here.