Display message on startup

If you would like to display a legal message or any other message in a pop-up window when windows starts read below:
Start regedit, if you are unfamiliar with regedit please see our FAQ.
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
Modify the key legalnoticecaption with what you want to name the window.
Modify the key legalnoticetext with what you want the window to say.
Restart.