Hide Users on the Welcome Screen
Windows XP
Registry Hack

<Username> = The user to be hidden's login name

in: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\SpecialAccounts\UserList\ 
create new: DWORD
	named: <Username>
	value: 0



To undo:
Either delete the value, or toggle the bit.