How can you customize the message window of the Windows Logon?

This type of operation can be useful for system administrator to show messages before the user logon...

you must modify the following registry keys, running the application regedit.exe:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]

edit or create (if doesn't exist) the following value:

"LegalNoticeText"="message you want to view when the operating system starts"

edit or create (if doesn't exist) the following value:

"LegalNoticeCaption"="message you want to view in the logon window"