First, make "Ctrl-Alt-Del" a necessary requirement to access the login screen by:
typing "netplwiz" in the Start Search. Then go to Advanced tab, check "require users to press Ctrl+Alt+Del".
Then, since Vista Home has no gpcedit.msc or secpol.msc feature, type "regedit" in the Start Search instead. After that, go to:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
Change the value of the dontdisplaylastusername keyword to 1.