You do not need to use KiXtart to display your message. Windows has a built-in mechanism to display a legal message prior the the logon screen. You will need to edit the following keys or use Group Policy to set the message.
the code below is only a fragment to show the keys and values that should be edited.
Code:
Select
Case $OS="WinNT"
$RegKey="HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\winlogon"
Case $OS="Win9x"
$RegKey="HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\winlogon"
EndSelect
; The legal message interferes with the autologon process and therefore will not be installed
; on computers configured for autologon.
$Autologon=ReadValue("$RegKey","AutoAdminLogon")
if @error = 2
$Autologon=0
endif
If $Autologon=0
$RC1=WriteValue($RegKey,"LegalNoticeCaption",$String1,"REG_SZ")
$RC2=WriteValue($RegKey,"LegalNoticeText",$String2,"REG_SZ")
endif