As you know,when we install the windows 7,we were prompt to create the username and password by default.So when we startup ,we must input a password to logon windows 7.Below will give you a simple guide about how to logon your windows 7.
1.Go to Control panel,click User Accounts.
2.Then in the new windows,click Remove your password
3.Now in the next windows,input your password and click Remove Password
3.Done,the next time you start your windows 7,you will auto logon to desktop directly.
Note:You can auto logon your windows 7 only when you only have one user account of your windows 7