Or you can do this if you dont like the registry
Go To Start-Settings-Control Panel-Users And Passwords
On the users tab, ensure there is a tick in the Users must enter a username
and password box
This activates the Users for this computer box
Click on the name you want to Autologon and then remove the tick from the
Users must enter a username and password box
Apply, and an Auto Logon screen asking for the user password appears
Ok and OK to finish, Reboot to autologon user