How to Remove a Password at Start Up From Windows
Windows displays a password-protected welcome screen at every computer reboot. This is for your own protection -- nobody else can see what you do in your user account. The feature is especially helpful when you have a few users for the same machine. However, if you are the only one using your computer, the password prompt can become an annoying task before you can begin your work. Fortunately, Windows also includes an option for an automatic log-on without the prompt.
Go to the "Start" menu and click "Control Panel."
Click "User Accounts and Family Safety" link and then click "User Accounts" link.
Click the "Users" tab in the newly opened "User Accounts" window. Click on your user name in the "Users for this computer" box and uncheck the "Users must enter a user name and password to use this computer" option.
Type in your current password in the pop-up window and click "Remove Password" button to confirm.
Restart your computer.