Windows XP Tips: Pop Up a Message at Start Up

To pop a banner which can contain any message you want to display just before a user is going to log on, go to the key: 

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System.  

  

Now create a new string Value in the right pane named LegalNoticeCaption and enter the value that you want to see in the Menu Bar. Now create yet another new string value and name it Legal NoticeText.

 Modify it and insert the message you want to display  each  time  Windows  boots.This  can  be  effectively  used  to  display  the company's private policy each time the user logs on to his NT box. 

"Windows  XP Tips: Pop Up a Message at Start Up "

Reference : techpraveen.com