Recreate Password file

If you want to reset the sys password, you can try to recreate password.

1. go to d:\oracle\1020\database and rename pwdxxx.ora as pwdxxx.ora.old.

2. Then in command prompt type orapwd file=d:\oracle\1020\database\pwdxxx.ora password=newpassword entries=5

3. Try to login sqlplus by using new password