Click on Start-Control Panel. When the Control Panel opens, then double click on the "User Accounts" icon. When that loads, click on the "Change the way users log on and off". When that loads, place a CHECK mark in the "Use the Welcome Screen" box, then click on the "Apply Options" button. Restart the computer.
If the computer was on a domain at work, you may also need to change the option which requires "Ctrl-Alt-Delete" to be pressed before the logon window loads.. If that's the case, click on Start-Run, type: CONTROL userpasswords2, then press the "Enter" key.. When the "user Accounts" window loads, click on the "Advanced" tab at the top, then UNCHECK the box that says: "Require users to press Ctrl-Alt-Delete", then click on "Apply", then OK.
Hope this helps.