Every time Windows 7 is started it asks you to select the username and enter the password to access your system. There is no doubt that this is a very important security measure to stop other people using your computer or changing your settings, but what if you are the only user of your computer?
In windows 7, you can easily get rid of the login prompt window, go through the following steps to do it.
Go to Start and type netplwiz in the Search box and hit Enter. The User Accounts dialogue box will be displayed as shown in following screenshot.
Now uncheck Users must a enter username and password to use this computer option and press OK. Thats all you need to do, now you will never see the login window again