When you start Windows 7, by default, you are required to present your logon password credentials in order to proceed.
However if you are the only user and if you do not wish to password protect your PC, you can turn it off and enable automatic LogOn to Windows 7.
To do so, type control userpasswords2 in Start search and hit enter.
This will open the User Accounts settings window.
Under the Users tab, un-check Users must enter a user name and password to use this computer.
Clip Apply > OK. Reboot.