Lost Oracle SYS and SYSTEM password?‎

Method 1: SQLPLUS (Tested on Windows Oracle‎
‎C:\sqlplus “/ as sysdba”‎
SQL> show user
USER is “SYS”‎
SQL> passw system
Changing password for system
New password:‎
Retype new password:‎
Password changed
SQL> quit

Next, we need to change the password of SYS:‎
C:\sqlplus system/oracle
SQL> passw sys
Changing password for sys
New password:‎
Retype new password:‎
Password changed
SQL> quit

You should now be able to log on the SYS and SYSTEM users, with the ‎passwords you just typed in.‎

Method 2: Creating pwd file (Tested on Windows Oracle‎
‎1.‎ Stop the Oracle service of the instance you want to change the passwords ‎of.‎
‎2.‎ Find the PWD###.ora file for this instance, this is usuallly located at ‎C:\oracle\ora81\database\, where ### is the SID of your database.‎
‎3.‎ Rename the PWD###.ora file to PWD###.ora.bak for obvious safety ‎reasons.‎
‎4.‎ Create a new pwd file by issuing the command:
Orapwd file=C:\oracle\ora81\database\PWD###.ora password=XXXXX

Where ### is the SID and XXXXX is the password you would like to use for ‎the SYS and INTERNAL accounts.‎
5.‎ Start the Oracle service for the instance you just fixed. You should be able to ‎get in with the SYS user and change other passwords from there.‎

Login with /@### as sysdba and try this command.‎