Here’s what you do to enable automatic log on to your Windows 7 user account
Hit WindowsKey+R and execute
On the dialog that opens, click on the username that you wish to enable automatic log on and uncheck the "Users must enter a user name and password to use this computer" checkbox.
When you click OK, Windows will ask the password for that user.
Type it twice to confirm and hit Ok.
From now on, the user account you selected will be automatically logged on when booting.