First time you try to login as scott/tiger, it would throw an error as shown below,
To get rid of this error, login as SYSTEM for password use the password that was speficied during step3 of this installation process.
Once logged in, use the sql statement below to unlock scott user.
Once this is done, login as scott tiger and it should work. It might as to change the old password with a new one, In this case use "tiger" as old password.