At the Search box or a command prompt, type control userpasswords2 and press Enter. The User Accounts screen appears.

Highlight the account that you want to automatically log on with, then uncheck the box next to Users must enter a user name and password to use this computer. Click OK.

The Automatically Log On dialog box appears. Type in the password for the account that you want to log on automatically. (If the account shown isn't the one that you want to log on automatically, type in the username and password for the correct account. Click OK.)

From now on, you'll automatically log in using that account. When you're logged in, if you want to switch to another account, use Fast User Switching: Click the Start button, click the arrow in the lower-right corner of the Start menu, and select Switch User. You'll come to a screen listing all users on your PC, where you can log in as any other user.