Windows 7 allowing you to customize it according to your need & use. Whether you change windows 7 logon screen background or enable or disable windows 7 automatic login. It offers a user friendly environment rather than windows Xp operating system.
Auto logon is a very convenient feature but it is generally not good from a security point of view. Most of us always say that it's just my home PC but you'd be surprised how many of those people also forget that they actually do have some sensitive data on their PC.
You can suppose it as windows 7 problems or windows 7 features, according to your use. If you are a home user of Windows 7, then you may want to auto login to Windows 7 without providing password each time you login. It’s also useful in the situations where you are doing some automated work on Windows and you want to be logged in automatically after system boot.
If you want to use Auto logon, then that's your personal choice. But just make sure you know and understand the risks. You can turn on or turn off automatic login feature in the following way:
Step1: Click "Start" button from taskbar and type "control userpasswords2" in the search box and press "Enter".
Step2: Now "User Accounts" window will be open. In the User Accounts window uncheck the "Users must enter a user name and password to use this computer" checkbox to enable automatic log on. After this the system will not ask for password while logging in OR check the Users must enter a user name and password to use this computer checkbox to disable automatic log on. After this the system will ask for password while logging in.