Click on Start and then Control Panel.
Click on the User Accounts and Family Safety link.
Click on the User Accounts link.
In the Make changes to your user account area of the User Accounts window, click the Remove your password link.
In the text box on the next screen, enter your current Windows 7 password.
Click the Remove Password button to confirm that you'd like to remove your Windows 7 password.
You can now close the User Accounts window.
Now that your Windows 7 account password has been deleted, you will no longer need to log on when your computer starts.