Go to Control Panel and double click User Accounts.
Under Pick a Task, click on "Change the way users log on or
off".
If you see a check mark next to "Use the Welcome Screen", you
will see the names and icons that you can click on to log on to
the system.
If it's unchecked, you will see the Logon to Windows dialog box
where you'll need to enter a user name and password to logon.
Keep in mind that the Welcome Screen is not available on a
computer joined to a domain.