Resetting password SYSTEM in Oracle is very easy,
1. Open your command line, and login as sysdba
<C:\>sqlplus "/as sysdba"
2. Update new password by altering user
alter user system identified by new_password
3. if your account has locked, you need to unlock first
alter user system identified by new_password account unlock
4. The last try to login as system
sqlplus system/new_password
That’s all …