أنا عملت للأوراكل10 set up بعد كده أشغلو تطلعلى رسالة مطلوب فيها 1. user name
2. password
host string .3:

user name: sys/sys as sysdba

after login write the following:

alter user system identified by manager;
alter user scott identified by tiger;

and then try to login again by using :

user name: scott
password: tiger

or

user name: system
password: manager

try it and tell me what you'll have...