You might want to have a banner pop up when a user is going to log on, a banner that contains any kind of message you want to display. This can be used to display the company’s policy, for example. Or a warning message to trespassers telling them to buzz off!
Navigate to:
HLM\SOFTWARE\Microsoft\WindowsNT
\CurrentVersion\WinLogon
Create a new String Value here called LegalNoticeCaption. Enter whatever you want to see in the bar at the top. Now create another new String Value called LegalNoticeText. Modify it to the message you want to display each time Windows boots.

The message will be displayed at the next logon.
