Lost SYSOPER Password

Thera are several solutions to this issue, you can use one of the following methods:

• Make sure that the database and listener services are started. Then open a command prompt and log in as / as sysdba. Then change the sys password.
  
  c:> sqlplus /nolog
  SQL> connect / as sysdba
  SQL> alter user sys identified by ;
  
  If you get asked for a password when you log in as / you need to create or recreate the password file using orapw. Check the $ORACLE_HOME/database directory for a file called orapw. That is the password file for the database. Create (or recreate) it using:
  
  c:\> orawpd file=$ORACLE_HOME/database/orapwd password= entries=5
  
  Notice it is from the dos prompt
• you may also try this method:
  
  1. login oracle user
  2. cd $ORACLE_HOME/network/admin
  3. ed(vi) file sqlnet.ora
     
  4. Remark by # at begining of line
     SQLNET.AUTHENTICATION_SERVICES = (NONE)
     => #SQLNET.AUTHENTICATION_SERVICES = (NONE)
  5. sqlplus /nolog or (svrmgrl) command
  6. connect sys as sysdba, or connect internal
     (not need input the password).