Hello, if you know the password to login you can follow the steps below to get rid of Windows 7 logon password:
1. Press the Windows key + R on your keyboard to launch the "Run" dialog box.
2. Type in "control userpasswords2" and press "Enter".
3. The User Accounts windows will display there. Uncheck the option "Users must enter a user name and password to use this computer" and click "OK".
4. Then you are asked to enter the current password. Confirm it.
5. After that, you can auto log on Windows 7 without password.