If you would like to have the old style user login welcome screen, much like Windows 95, 2000, etc where it prompts you for the user name and password to sign in, follow these steps:

1) In your Start Menu search box (located at the bottom of your Start Menu, type 'local' and you should see the "Local Security Policy" title listed.  

2) Navigate to "Local Policy"

3) Navigate to "User Rights Assignment"

4) Locate on the right side and double click on "Interactive Logon: Do not display last user name".  Enable this option and the welcome screen will not longer display the icons of users and their names, it will have a simple user name and password box to enter the information.

That should take care of it!

PS.  While you are in that area, there is also the option below the one above called "Interactive logon: Do not require CTRL-ALT-DEL". If you enable this, it will require users to hit the CRTL-ALT-DEL keys to get the sign in window to appear.  Just another step of security.