You need to type the command: net user user_name new_password and enter. There is no username and password you can login directly in a Windows 7. The only solution is to reset the password in the system.
How can I bypass a Windows 7 password?
If you want to bypass Windows 7 password, type the command: net user user_name new_password. User name is your own username and new password is the password you choose. Then restart the computer to login with the reset password.