Chang to the Classic Logon Screen

Classic logon screen, where all user accounts are hidden from the Welcome screen and both a username and a password are required to log on, then do this:

Type secpol.msc in Vista's Start Menu Search Bar and hit Enter. This will open the Local Security Policy editor.
Navigate to Security Settings > Local Policies > Security Options

Look for Interactive Logon: Hide last username on the Right Hand Side. Set it to Enabled. Click Apply. Then close that window.

To Enable CTRL-ALT-DELETE Key Combo before login:

Type netplwiz in the Start Menu search box and hit Enter. This will open up the User Accounts dialog box. Select Advanced tab > Secure logon. Check Require users to press Ctrl+Alt+Delete. Click Apply. Then Reboot.
This guarantees that the authentic Windows logon prompt appears, protecting the system from programs that mimic a logon to retrieve passwords.